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For more info see http://www.lyx.org/ \lyxformat 544 \begin_document \begin_header \save_transient_properties true \origin unavailable \textclass book \begin_preamble % Added by lyx2lyx % for proper underlining \PassOptionsToPackage{normalem}{ulem} \usepackage{ulem} \let\cite@rig\cite \newcommand{\b@xcite}[2][\%]{\def\def@pt{\%}\def\pas@pt{#1} \mbox{\ifx\def@pt\pas@pt\cite@rig{#2}\else\cite@rig[#1]{#2}\fi}} \renewcommand{\underbar}[1]{{\let\cite\b@xcite\uline{#1}}} \pdfoptionpdfminorversion=3 % \sloppy \tolerance=500 \emergencystretch=30pt % \date{} \end_preamble \use_default_options false \begin_modules logicalmkup \end_modules \maintain_unincluded_children false \language english \language_package default \inputencoding utf8 \fontencoding global \font_roman "times" "default" \font_sans "helvet" "default" \font_typewriter "courier" "default" \font_math "auto" "auto" \font_default_family default \use_non_tex_fonts false \font_sc false \font_osf false \font_sf_scale 100 100 \font_tt_scale 100 100 \use_microtype false \use_dash_ligatures false \graphics default \default_output_format default \output_sync 0 \bibtex_command default \index_command default \paperfontsize default \spacing single \use_hyperref true \pdf_title "SDCC Compiler User Guide" \pdf_author "SDCC development team" \pdf_subject "installation, user manual" \pdf_keywords "68hc08 8032 8051 ansi iso c compiler assembler CPU DS390 embedded development free Floating Point Arithmetic Freescale GPL HC08 S08 inline Intel ISO/IEC 9899:1990 Linux MAC OS X manual Maxim mcs51 Microchip microcontroller open source PIC Unix Windows Z80 Z180 Zilog Rabbit" \pdf_bookmarks true \pdf_bookmarksnumbered false \pdf_bookmarksopen false \pdf_bookmarksopenlevel 1 \pdf_breaklinks false \pdf_pdfborder false \pdf_colorlinks true \pdf_backref false \pdf_pdfusetitle true \papersize letterpaper \use_geometry true \use_package amsmath 1 \use_package amssymb 1 \use_package cancel 1 \use_package esint 0 \use_package mathdots 1 \use_package mathtools 1 \use_package mhchem 1 \use_package stackrel 1 \use_package stmaryrd 1 \use_package undertilde 1 \cite_engine basic \cite_engine_type default \biblio_style plain \use_bibtopic false \use_indices false \paperorientation portrait \suppress_date false \justification true \use_refstyle 0 \use_minted 0 \branch test \selected 0 \filename_suffix 0 \color #faf0e6 \end_branch \index Index \shortcut idx \color #008000 \end_index \leftmargin 30mm \topmargin 20mm \rightmargin 25mm \bottommargin 20mm \secnumdepth 3 \tocdepth 3 \paragraph_separation indent \paragraph_indentation default \is_math_indent 0 \math_numbering_side default \quotes_style swedish \dynamic_quotes 0 \papercolumns 1 \papersides 1 \paperpagestyle fancy \tracking_changes false \output_changes false \html_math_output 0 \html_css_as_file 0 \html_be_strict false \end_header \begin_body \begin_layout Standard \begin_inset Note Note status collapsed \begin_layout Plain Layout Please note: double dashed longoptions (e.g. –version) are written this way: - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset - \end_layout \begin_layout Plain Layout Two resp. three consecutive dashes would otherwise result in a long resp. extra long dash. \end_layout \begin_layout Plain Layout Architecture specific stuff (like memory models, code examples) should maybe later go \end_layout \begin_layout Plain Layout into separate sections/chapters/appendices (it is hard to document PIC or Z80 in \end_layout \begin_layout Plain Layout a 8051 centered document) - for now simply add. \end_layout \end_inset \end_layout \begin_layout Title SDCC Compiler User Guide \end_layout \begin_layout Date \size normal SDCC \begin_inset CommandInset include LatexCommand input filename "sdcc_version" \end_inset \begin_inset Newline newline \end_inset \size footnotesize $Date:: 2019-04-24 #$ \begin_inset Newline newline \end_inset $Revision: 11239 $ \end_layout \begin_layout Standard \begin_inset Note Note status collapsed \begin_layout Plain Layout The above strings enclosed in $ are automatically updated by Subversion \end_layout \end_inset \end_layout \begin_layout Standard \begin_inset CommandInset toc LatexCommand tableofcontents \end_inset \end_layout \begin_layout Chapter Introduction \end_layout \begin_layout Section About SDCC \end_layout \begin_layout Standard \series bold SDCC \series default ( \emph on S \emph default mall \emph on D \emph default evice \emph on C \emph default \emph on C \emph default ompiler) is free open source, retargettable, optimizing standard (ANSI C89 / ISO C90, ISO C99, ISO C11 / ISO C17) C compiler suite originally written by \series bold Sandeep Dutta \series default designed for 8 bit Microprocessors. The current version targets Intel MCS51 based Microprocessors (8031, 8032, 8051, 8052 \begin_inset Index idx status collapsed \begin_layout Plain Layout 8031, 8032, 8051, 8052, mcs51 CPU \end_layout \end_inset , etc.), Dallas DS80C390 variants, Freescale (formerly Motorola) HC08 based (hc08, s08), Zilog Z80 based MCUs (Z80, Z180, gbz80, Rabbit 2000/3000, Rabbit 3000A \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80, Z180, GBZ80, Rabbit 2000/3000, Rabbit 3000A CPU \end_layout \end_inset ), Toshiba TLCS-90, Zilog eZ80 in Z80 mode, STMicroelectronics STM8 \begin_inset Index idx status collapsed \begin_layout Plain Layout STM8 \end_layout \end_inset and Padauk PDK14. It can be retargeted for other microprocessors, support for Microchip PIC and Padauk PDK15 is under development. The entire source code for the compiler is distributed under GPL. SDCC uses a modified version of ASXXXX \begin_inset Index idx status collapsed \begin_layout Plain Layout sdas (sdasgb, sdas6808, sdas8051, sdasz80) \end_layout \end_inset & ASLINK \begin_inset Index idx status collapsed \begin_layout Plain Layout sdld \end_layout \end_inset , free open source retargetable assembler & linker. SDCC has extensive language extensions suitable for utilizing various microcont rollers and underlying hardware effectively. \begin_inset Newline newline \end_inset You might also want to have a look at the wiki \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/wiki/ \end_layout \end_inset . \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset In addition to the MCU specific optimizations SDCC also does a host of standard optimizations like: \end_layout \begin_layout Itemize global sub expression elimination, \end_layout \begin_layout Itemize loop optimizations (loop invariant, strength reduction of induction variables and loop reversing), \end_layout \begin_layout Itemize constant folding & propagation, \end_layout \begin_layout Itemize copy propagation, \end_layout \begin_layout Itemize dead code elimination \end_layout \begin_layout Itemize jump tables for \emph on switch \emph default statements. \end_layout \begin_layout Standard For the back-end SDCC uses a global register allocation scheme which should be well suited for other 8 bit MCUs. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset The peep hole optimizer uses a rule based substitution mechanism which is MCU independent. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Supported data-types are: \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout type \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout width \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout default \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout signed range \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout unsigned range \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout _Bool / bool \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 8 bits, 1 byte \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout unsigned \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0, 1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout char \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 8 bits, 1 byte \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout unsigned \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout -128, +127 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0, +255 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout short \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 16 bits, 2 bytes \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout signed \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout -32.768, +32.767 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0, +65.535 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout int \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 16 bits, 2 bytes \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout signed \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout -32.768, +32.767 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0, +65.535 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout long \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 32 bits, 4 bytes \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout signed \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout -2.147.483.648, +2.147.483.647 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0, +4.294.967.295 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout long long \begin_inset Foot status open \begin_layout Plain Layout Incomplete support in the pic14 and pic16 backends. \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 64 bits, 8 bytes \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout signed \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout float \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 4 bytes similar to IEEE 754 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout signed \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1.175494351E-38, \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none 3.402823466E+38 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout pointer \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1, 2, 3 or 4 bytes \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout generic \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __bit \begin_inset Foot status open \begin_layout Plain Layout Only supported in the mcs51, ds390, ds400 backends. \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1 bit \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout unsigned \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0, 1 \end_layout \end_inset \end_inset \begin_inset Newline newline \end_inset The compiler also allows \emph on inline assembler code \emph default to be embedded anywhere in a function. In addition, routines developed in assembly can also be called. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset SDCC also provides an option (- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -cyclomatic) to report the relative complexity of a function. These functions can then be further optimized, or hand coded in assembly if needed. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset SDCC also comes with a companion source level debugger SDCDB. The debugger currently uses ucSim, a free open source simulator for 8051 and other micro-controllers. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset The latest SDCC version can be downloaded from \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/snap.php \end_layout \end_inset . \emph on Please note: the compiler will probably always be some steps ahead of this documentation \series bold \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout Status of documentation \end_layout \end_inset \begin_inset Foot status collapsed \begin_layout Plain Layout Obviously this has pros and cons \end_layout \end_inset . \end_layout \begin_layout Section SDCC Suite Licenses \end_layout \begin_layout Standard SDCC suite is a collection of several components derived from different sources with different licenses: \end_layout \begin_layout Itemize executables: \begin_inset Separator latexpar \end_inset \end_layout \begin_deeper \begin_layout Itemize sdcc compiler: \begin_inset Newline newline \end_inset sdcc compiler is licensed under the GPLv2. \begin_inset Newline newline \end_inset The code or object files generated by SDCC suite are not licensed, so they can be used in FLOSS or proprietary (closed source) applications. \end_layout \begin_layout Itemize sdcpp preprocessor: \begin_inset Newline newline \end_inset derived from GCC cpp preprocessor \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://gcc.gnu.org/ \end_layout \end_inset ; GPLv3 license \end_layout \begin_layout Itemize sdas assemblers and sdld linker: \begin_inset Newline newline \end_inset derived from ASXXXX \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://shop-pdp.kent.edu/ashtml/asxxxx.htm \end_layout \end_inset ; GPLv3 license \end_layout \begin_layout Itemize SDCC run-time libraries: \begin_inset Newline newline \end_inset The great majority of SDCC run-time libraries are licensed under the GPLv2+LE \begin_inset Index idx status collapsed \begin_layout Plain Layout GPLv2+LE \end_layout \end_inset which allows linking of SDCC run-time libraries with proprietary (closed source) applications. \begin_inset Newline newline \end_inset Exception are pic device libraries and header files which are derived from Microchip header (.inc) and linker script (.lkr) files. Microchip requires that "The header files should state that they are only to be used with authentic Microchip devices" which makes them incompatible with the GPL. Pic device libraries and header files are located at non-free/lib and non-free/ include directories respectively. SDCC should be run with the \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset - \series default use-non-free \series bold \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-non-free \end_layout \end_inset \series default command line option in order to include non-free header files and libraries. \end_layout \begin_layout Itemize sdbinutils utilities (sdar, sdranlib, sdnm, sdobjcopy): \begin_inset Newline newline \end_inset derived from GNU Binutils \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.gnu.org/software/binutils/ \end_layout \end_inset ; GPLv3 license \end_layout \begin_layout Itemize ucsim simulators: \begin_inset Newline newline \end_inset GPLv2 license \end_layout \begin_layout Itemize sdcdb debugger: \begin_inset Newline newline \end_inset GPLv2 license \end_layout \begin_layout Itemize gcc-test regression tests: \begin_inset Newline newline \end_inset derived from gcc-testsuite; no license explicitely specified, but since it is a part of GCC is probably GPLv3 licensed \end_layout \begin_layout Itemize packihx: \begin_inset Newline newline \end_inset public domain \end_layout \begin_layout Itemize makebin: \begin_inset Newline newline \end_inset zlib/libpng License \end_layout \end_deeper \begin_layout Itemize libraries: \begin_inset Separator latexpar \end_inset \end_layout \begin_deeper \begin_layout Itemize dbuf library: \begin_inset Newline newline \end_inset zlib/libpng License \end_layout \begin_layout Itemize Boost C++ libraries: \begin_inset Newline newline \end_inset \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.boost.org/ \end_layout \end_inset ; Boost Software License 1.0 (BSL-1.0) \end_layout \end_deeper \begin_layout Standard Links to licenses: \end_layout \begin_layout Itemize GPLv2 license \begin_inset Index idx status collapsed \begin_layout Plain Layout GPLv2 license \end_layout \end_inset : \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.gnu.org/licenses/old-licenses/gpl-2.0.html \end_layout \end_inset \end_layout \begin_layout Itemize LGPLv2.1 license \begin_inset Index idx status collapsed \begin_layout Plain Layout LGPLv2.1 license \end_layout \end_inset : \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html \end_layout \end_inset \end_layout \begin_layout Itemize GPLv3 license \begin_inset Index idx status collapsed \begin_layout Plain Layout GPLv3 license \end_layout \end_inset : \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.gnu.org/licenses/gpl.html \end_layout \end_inset \end_layout \begin_layout Itemize zlib/libpng License \begin_inset Index idx status collapsed \begin_layout Plain Layout zlib/libpng License \end_layout \end_inset : \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.opensource.org/licenses/Zlib \end_layout \end_inset \end_layout \begin_layout Itemize Boost Software License 1.0 (BSL-1.0) \begin_inset Index idx status collapsed \begin_layout Plain Layout Boost Software License 1.0 (BSL-1.0) \end_layout \end_inset : \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.opensource.org/licenses/BSL-1.0 \end_layout \end_inset \end_layout \begin_layout Section Documentation \end_layout \begin_layout Standard This documentation is maintained using a free open source word processor (\SpecialChar LyX ) \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.lyx.org/ \end_layout \end_inset . \end_layout \begin_layout Section Typographic conventions \begin_inset Index idx status collapsed \begin_layout Plain Layout Typographic conventions \end_layout \end_inset \end_layout \begin_layout Standard Throughout this manual, we will use the following convention. Commands you have to type in are printed in \family sans \series bold "sans serif" \series default . \family default Code samples are printed in \family typewriter typewriter font. \family default Interesting items and new terms are printed in \emph on italic. \end_layout \begin_layout Section Compatibility \begin_inset CommandInset label LatexCommand label name "sec:Compatibility-with-previous" \end_inset with previous versions \begin_inset Index idx status collapsed \begin_layout Plain Layout Compatibility with previous versions \end_layout \end_inset \end_layout \begin_layout Standard Newer versions have usually numerous bug fixes compared with the previous version. But we also sometimes introduce some incompatibilities with older versions. Not just for the fun of it, but to make the compiler more stable, efficient and standard compliant \begin_inset Index idx status collapsed \begin_layout Plain Layout Standard-compliance \end_layout \end_inset (see section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Standard-Compliance" \end_inset for Standard-Compliance). This is a list of such changes . \begin_inset Note Note status collapsed \begin_layout Plain Layout It would be fine to add to each item, in which version was it changed. \end_layout \end_inset \end_layout \begin_layout Itemize short is now equivalent to int (16 bits), it used to be equivalent to char (8 bits) which is not ANSI compliant. To maintain compatibility, old programs could be compiled using the - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -short-is-8bits command line option (option removed after the 3.6.0 release). \end_layout \begin_layout Itemize the default directory for gcc-builds where include, library and documentation files are stored is now in /usr/local/share. \end_layout \begin_layout Itemize char type parameters to vararg \begin_inset Index idx status collapsed \begin_layout Plain Layout vararg, va \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset arg \end_layout \end_inset functions are casted to int unless explicitly casted and \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c89 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c89 \end_layout \end_inset \series default and \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c99 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c99 \end_layout \end_inset \series default command line option are not defined, e.g.: \begin_inset Newline newline \end_inset \family typewriter \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset char a=3; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset printf ("%d %c \backslash n", a, (char)a); \family default \begin_inset Newline newline \end_inset will push a as an int and as a char resp if \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c89 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c89 \end_layout \end_inset \series default and \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c99 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c99 \end_layout \end_inset \series default command line options are not defined, \begin_inset Newline newline \end_inset will push a as two ints if \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c89 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c89 \end_layout \end_inset \series default or \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c99 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c99 \end_layout \end_inset \series default command line option is defined. \end_layout \begin_layout Itemize pointer type parameters to vararg \begin_inset Index idx status collapsed \begin_layout Plain Layout vararg, va \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset arg \end_layout \end_inset functions are casted to generic pointers on Harvard architectures (e.g. mcs51, ds390) unless explicitly casted and \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c89 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c89 \end_layout \end_inset \series default and \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c99 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c99 \end_layout \end_inset \series default command line option are not defined. \end_layout \begin_layout Itemize option - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -regextend has been removed. \end_layout \begin_layout Itemize option - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -noregparms has been removed. \end_layout \begin_layout Itemize option - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-after-data has been removed. \end_layout \begin_layout Itemize bit \begin_inset Index idx status collapsed \begin_layout Plain Layout bit \end_layout \end_inset and sbit \begin_inset Index idx status collapsed \begin_layout Plain Layout sbit \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset sbit \end_layout \end_inset types now consistently behave like the C99 _Bool type with respect to type conversion \begin_inset Index idx status collapsed \begin_layout Plain Layout type conversion \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout type promotion \end_layout \end_inset . The most common incompatibility resulting from this change is related to bit toggling \begin_inset Index idx status collapsed \begin_layout Plain Layout Bit toggling \end_layout \end_inset idioms, e.g.: \begin_inset Newline newline \end_inset \family typewriter \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset bit b; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset b = ~ \begin_inset Index idx status collapsed \begin_layout Plain Layout ~ Operator \end_layout \end_inset b; /* equivalent to b=1 instead of toggling b */ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset b = !b; /* toggles b */ \begin_inset Newline newline \end_inset \family default In previous versions, both forms would have toggled the bit. \end_layout \begin_layout Itemize in older versions, the preprocessor was always called with \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c99 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c99 \end_layout \end_inset \series default regardless of the \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-xxx \series default setting. This is no longer true, and can cause compilation failures on code built with \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c89 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c89 \end_layout \end_inset \series default but using c99 preprocessor features, such as one-line (//) comments \end_layout \begin_layout Itemize in versions older than 2.8.4 the pic16 *printf() and printf_tiny() library functions supported undocumented and not standard compliant 'b' binary format specifier ("%b", "%hb" and "%lb"). The 'b' specifier is now disabled by default. It can be enabled by defining BINARY_SPECIFIER macro in files device/lib/pic16/ libc/stdio/vfprintf.c and device/lib/pic16/libc/stdio/printf_tiny.c and recompilin g the library. \end_layout \begin_layout Itemize in versions older then 2.8.5 the unnamed bit-field structure members participated in initialization, which is not conforming with ISO/IEC 9899:1999 standard (see section Section 6.7.8 Initialization, clause 9) \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Old behaviour, before version 2.8.5: \family typewriter \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset struct { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset int a : 2; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset char \begin_inset space ~ \end_inset : 2; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset int b : 2; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset } s = {1, 2, 3}; \family default \begin_inset Newline newline \end_inset \family typewriter /* s.a = 1, s.b = 3 */ \family default \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset New behaviour: \family typewriter \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset struct { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset int a : 2; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset char \begin_inset space ~ \end_inset : 2; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset int b : 2; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset } s = {1, 2}; \family default \begin_inset Newline newline \end_inset \family typewriter /* s.a = 1, s.b = 2 */ \end_layout \begin_layout Itemize In 2.9.0 libraries included in SDCC packages, are in ar format. See section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Using-sdar-to" \end_inset . \end_layout \begin_layout Itemize In 3.0.0 targets for xa51 and avr are disabled by default. \end_layout \begin_layout Itemize In 3.0.0 sdldgb and sdldz80 don't support generation of Game Boy binary image format. The makebin utility can be used to convert Intel Hex format to Game Boy binary image format. \end_layout \begin_layout Itemize In 3.0.0 sdldgb and sdldz80 don't support generation of rrgb (Game Boy simulator) map file and no$gmb symbol file formats. The as2gbmap utility can be used to convert sdld map format to rrgb and no$gmb file formats. \end_layout \begin_layout Itemize In 3.1.0 asranlib utility was renamed to sdranlib. \end_layout \begin_layout Itemize In 3.1.0 pic14 target, structured access to SFR via \family typewriter _bits. \family default is deprecated and replaced by \family typewriter bits. \family default . It will be obsoleted (removed) in one of next SDCC releases. See section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Naming-of-special" \end_inset . \end_layout \begin_layout Itemize sdar archive managing utility and sdnm utilities were introduced in version 3.2.0. sdar, sdranlib and sdnm are derived from GNU Binutils package. \end_layout \begin_layout Itemize In 3.2.0 the sdcclib utility is deprecated. Sdar utility should be used to create SDCC object file archives. Sdcclib utility will become obsolete in one of next SDCC releases and will be removed from SDCC packages. \end_layout \begin_layout Itemize In 3.2.0 special SDCC keywords which are not preceded by a double underscore are obsoleted (removed). See section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Standard-Compliance" \end_inset Standard-Compliance. \end_layout \begin_layout Itemize In 3.2.0 compiler macro definitions not starting with double underscore characters are deprecated if \begin_inset Flex Code status open \begin_layout Plain Layout --std-cXX \end_layout \end_inset command line option is defined. They have been obsoleted (removed) after the 3.4.0 release (except for the macro SDCC, which has been removed after the 3.6.0 release (and brought back for mcs51 for the 3.7.0 release)). \end_layout \begin_layout Itemize In 3.2.0 new compiler macros for processor definition were introduced for pic14 and pic16 targets: -D__SDCC_PIC16XXXX and -D__SDCC_PIC18FXXX respectively. The pic16 macro definition -D__18fXXX is deprecated. It was obsoleted (removed) after the 3.4.0 release. \end_layout \begin_layout Itemize In 3.2.0 pragma config for pic16 target was introduced. See section \begin_inset CommandInset ref LatexCommand ref reference "subsec:PIC16_Pragmas" \end_inset \end_layout \begin_layout Itemize In 3.2.0 new inline assembler format \family typewriter __asm__ (inline_assembler_code \begin_inset Quotes srd \end_inset ); \family default as an addition to \family typewriter __asm ... __endasem; \family default format introduced. See section \begin_inset CommandInset ref LatexCommand ref reference "sec:Inline-Assembler-Code" \end_inset \end_layout \begin_layout Itemize sdobjcopy utility was introduced in version 3.3.0. It is derived from GNU Binutils package. \end_layout \begin_layout Itemize Before 3.4.0 release, intrinsic named address spaces were called \begin_inset Quotes sld \end_inset storage classes \begin_inset Quotes srd \end_inset in this manual. \end_layout \begin_layout Itemize In 3.6.0, the default for char changed from signed to unsigned. \end_layout \begin_layout Itemize In 3.7.0, the prototype for putchar() changed from void putchar(char) to int putchar(int) \end_layout \begin_layout Itemize In 3.7.0 mcs51 and ds390 got a full _Bool/bool type, separate from __bit. \end_layout \begin_layout Itemize In 3.7.0, the option –nojtbound and the corresponding pragma have been deprecated. \end_layout \begin_layout Itemize In 3.7.0, the prototype for getchar() changed from char getchar(void) to int getchar(). \end_layout \begin_layout Itemize In 3.8.6, the deprecated sdcclib was removed. \end_layout \begin_layout Section System Requirements \end_layout \begin_layout Standard What do you need before you start installation of SDCC? A computer, and a desire to compute. The preferred method of installation is to compile SDCC from source using GNU GCC and make. For Windows some pre-compiled binary distributions are available for your convenience. You should have some experience with command line tools and compiler use. \end_layout \begin_layout Section Other Resources \end_layout \begin_layout Standard The SDCC home page at \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/ \end_layout \end_inset is a great place to find distribution sets. You can also find links to the user mailing lists that offer help or discuss SDCC with other SDCC users. Web links to other SDCC related sites can also be found here. This document can be found in the doc directory of the source package. The latest snapshot build version of this document in pdf format is available at \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/doc/sdccman.pdf \end_layout \end_inset . Some of the other tools (simulator and assembler) included with SDCC contain their own documentation and can be found in the source distribution. If you want the latest unreleased software, the complete source package is available directly from Subversion on \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/p/sdcc/code/8805/tree/trunk/sdcc/ \end_layout \end_inset . \end_layout \begin_layout Chapter Installing SDCC \begin_inset Index idx status collapsed \begin_layout Plain Layout Installation \end_layout \end_inset \end_layout \begin_layout Standard For most users it is sufficient to skip to either section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Building-SDCC-on-Linux" \end_inset (Unix) or section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Windows-Install" \end_inset (Windows). More detailed instructions follow below. \end_layout \begin_layout Section Configure Options \begin_inset Index idx status collapsed \begin_layout Plain Layout Options SDCC configuration \end_layout \end_inset \end_layout \begin_layout Standard The install paths, search paths and other options are defined when running 'configure'. The defaults can be overridden by: \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -prefix see table below \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -exec_prefix see table below \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -bindir see table below \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -datadir see table below \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -datarootdir see table below \begin_inset Newline newline \end_inset \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset docdir environment variable, see table below \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset include_dir_suffix environment variable, see table below \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset non_free_include_dir_suffix environment variable, see table below \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset lib_dir_suffix environment variable, see table below \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset non_free_lib_dir_suffix environment variable, see table below \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdccconf_h_dir_separator environment variable, either / or \backslash \backslash makes sense here. This character will only be used in sdccconf.h; don't forget it's a C-header, therefore a double-backslash is needed there. \begin_inset Newline newline \end_inset \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-mcs51-port Excludes the Intel mcs51 port \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-z80-port Excludes the z80 port \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-z180-port Excludes the z180 port \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-r2k-port Excludes the r2k port \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-r3ka-port Excludes the r3ka port \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-gbz80-port Excludes the Game Boy gbz80 port \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-avr-port Excludes the AVR port (disabled by default) \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-ds390-port Excludes the DS390 port \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-hc08-port Excludes the HC08 port \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-s08-port Excludes the S08 port \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-stm8-port Excludes the STM8 port \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-pic-port Excludes the PIC14 port \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-pic16-port Excludes the PIC16 port \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-xa51-port Excludes the XA51 port (disabled by default) \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-ucsim Disables configuring and building of ucsim \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-device-lib Disables automatically building device libraries \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-packihx Disables building packihx \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -enable-doc Build pdf, html and txt files from the lyx sources \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -enable-libgc Use the Bohem memory allocator. Lower runtime footprint. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -without-ccache Do not use ccache even if available \end_layout \begin_layout Standard Furthermore the environment variables CC, CFLAGS, ... the tools and their arguments can be influenced. Please see `configure - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -help' and the man/info pages of `configure' for details. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset The names of the standard libraries STD_LIB, STD_INT_LIB, STD_LONG_LIB, STD_FP_LIB, STD_DS390_LIB, STD_XA51_LIB and the environment variables SDCC_DIR_ NAME, SDCC_INCLUDE_NAME, SDCC_LIB_NAME are defined by `configure' too. At the moment it's not possible to change the default settings (it was simply never required). \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset These configure options are compiled into the binaries, and can only be changed by rerunning 'configure' and recompiling SDCC. The configure options are written in \emph on italics \emph default to distinguish them from run time environment variables (see section search paths). \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset The settings for \begin_inset Quotes sld \end_inset Win32 builds \begin_inset Quotes srd \end_inset are used by the SDCC team to build the official Win32 binaries. The SDCC team uses Mingw32 to build the official Windows binaries, because it's \end_layout \begin_layout Enumerate open source, \end_layout \begin_layout Enumerate a gcc compiler and last but not least \end_layout \begin_layout Enumerate the binaries can be built by cross compiling on SDCC Distributed Compile Farm. \end_layout \begin_layout Standard See the examples, how to pass the Win32 settings to 'configure'. The other Win32 builds using VC or whatever don't use 'configure', but a header file sdcc_vc.h.in is the same as sdccconf.h built by 'configure' for Win32. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset These defaults are: \begin_inset Newline newline \end_inset \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout Variable \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout default \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Win32 builds \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on PREFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout /usr/local \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \backslash sdcc \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on EXEC_PREFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $PREFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $PREFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on BINDIR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $EXEC_PREFIX \emph default /bin \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $EXEC_PREFIX \emph default \backslash bin \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on DATADIR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $DATAROOTDIR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $DATAROOTDIR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on DATAROOTDIR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $PREFIX \emph default /share \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $PREFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on DOCDIR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $DATAROOTDIR \emph default /sdcc/doc \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $DATAROOTDIR \emph default \backslash doc \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on INCLUDE_DIR_SUFFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout sdcc/include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on NON_FREE_INCLUDE_DIR_SUFFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout sdcc/non-free/include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout non-free/include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on LIB_DIR_SUFFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout sdcc/lib \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout lib \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on NON_FREE_LIB_DIR_SUFFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout sdcc/non-free/lib \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout non-free/lib \end_layout \end_inset \end_inset \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard \noindent 'configure' also computes relative paths. This is needed for full relocatability of a binary package and to complete search paths (see section search paths below): \begin_inset Newline newline \end_inset \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout Variable (computed) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout default \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Win32 builds \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on BIN2DATA_DIR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout ../share \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout .. \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on PREFIX2BIN_DIR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout bin \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout bin \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on PREFIX2DATA_DIR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout share/sdcc \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \end_inset \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard \noindent Examples: \end_layout \begin_layout LyX-Code ./configure \begin_inset Newline newline \end_inset ./configure - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -prefix= \begin_inset Quotes srd \end_inset /usr/bin \begin_inset Quotes srd \end_inset - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -datarootdir= \begin_inset Quotes srd \end_inset /usr/share \begin_inset Quotes srd \end_inset \begin_inset Newline newline \end_inset ./configure - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-avr-port - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-xa51-port \end_layout \begin_layout Standard To cross compile on linux for Mingw32 (see also 'sdcc/support/scripts/sdcc_mingw 32'): \end_layout \begin_layout LyX-Code ./configure \backslash \begin_inset Newline newline \end_inset CC= \begin_inset Quotes srd \end_inset i586-mingw32msvc-gcc \begin_inset Quotes srd \end_inset CXX= \begin_inset Quotes srd \end_inset i586-mingw32msvc-g++ \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset RANLIB= \begin_inset Quotes srd \end_inset i586-mingw32msvc-ranlib \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset STRIP= \begin_inset Quotes srd \end_inset i586-mingw32msvc-strip \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -prefix= \begin_inset Quotes srd \end_inset /sdcc \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -datarootdir= \begin_inset Quotes srd \end_inset /sdcc \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset docdir= \begin_inset Quotes srd \end_inset \backslash ${datarootdir}/doc \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset include_dir_suffix= \begin_inset Quotes srd \end_inset include \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset non_free_include_dir_suffix= \begin_inset Quotes srd \end_inset non-free/include \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset lib_dir_suffix= \begin_inset Quotes srd \end_inset lib \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset non_free_lib_dir_suffix= \begin_inset Quotes srd \end_inset non-free/lib \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset sdccconf_h_dir_separator= \begin_inset Quotes srd \end_inset \backslash \backslash \backslash \backslash \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-device-lib \backslash \begin_inset Newline newline \end_inset - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -host=i586-mingw32msvc \backslash \begin_inset Newline newline \end_inset - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -build=unknown-unknown-linux-gnu \end_layout \begin_layout Standard To \begin_inset Quotes sld \end_inset cross \begin_inset Quotes srd \end_inset compile on Cygwin for Mingw32 (see also sdcc/support/scripts/sdcc_cygwin_mingw32 ): \end_layout \begin_layout LyX-Code ./configure -C \backslash \begin_inset Newline newline \end_inset - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -prefix= \begin_inset Quotes srd \end_inset /sdcc \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -datarootdir= \begin_inset Quotes srd \end_inset /sdcc \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset docdir= \begin_inset Quotes srd \end_inset \backslash ${datarootdir}/doc \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset include_dir_suffix= \begin_inset Quotes srd \end_inset include \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset non_free_include_dir_suffix= \begin_inset Quotes srd \end_inset non-free/include \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset lib_dir_suffix= \begin_inset Quotes srd \end_inset lib \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset non_free_lib_dir_suffix= \begin_inset Quotes srd \end_inset non-free/lib \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset sdccconf_h_dir_separator= \begin_inset Quotes srd \end_inset \backslash \backslash \backslash \backslash \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset CC= \begin_inset Quotes srd \end_inset gcc -mno-cygwin \begin_inset Quotes srd \end_inset \backslash \begin_inset Newline newline \end_inset CXX= \begin_inset Quotes srd \end_inset g++ -mno-cygwin \begin_inset Quotes srd \end_inset \end_layout \begin_layout Standard 'configure' is quite slow on Cygwin (at least on windows before Win2000/XP). The option '- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -C' turns on caching, which gives a little bit extra speed. However if options are changed, it can be necessary to delete the config.cache file. \end_layout \begin_layout Section Install paths \begin_inset CommandInset label LatexCommand label name "subsec:Install-paths" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Install paths \end_layout \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout \series bold Description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold Path \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold Default \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold Win32 builds \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Binary files* \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $EXEC_PREFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout /usr/local/bin \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \backslash sdcc \backslash bin \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Include files \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $DATADIR/ \emph default \begin_inset Newline newline \end_inset \emph on $INCLUDE_DIR_SUFFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout /usr/local/share/ \begin_inset Newline newline \end_inset sdcc/include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \backslash sdcc \backslash include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Non-free include files \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $DATADIR/non-free/ \emph default \begin_inset Newline newline \end_inset \emph on $INCLUDE_DIR_SUFFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout /usr/local/share/ \begin_inset Newline newline \end_inset sdcc/non-free/include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \backslash sdcc \backslash non-free \backslash include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Library file** \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $DATADIR/ \emph default \begin_inset Newline newline \end_inset \emph on $LIB_DIR_SUFFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout /usr/local/share/ \begin_inset Newline newline \end_inset sdcc/lib \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \backslash sdcc \backslash lib \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Library file** \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $DATADIR/non-free/ \emph default \begin_inset Newline newline \end_inset \emph on $LIB_DIR_SUFFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout /usr/local/share/ \begin_inset Newline newline \end_inset sdcc/non-free/lib \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \backslash sdcc \backslash non-free \backslash lib \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Documentation \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $DOCDIR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout /usr/local/share/ \begin_inset Newline newline \end_inset sdcc/doc \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \backslash sdcc \backslash doc \end_layout \end_inset \end_inset \end_layout \begin_layout Verse \size footnotesize *compiler, preprocessor, assembler, and linker \begin_inset Newline newline \end_inset **the \shape italic model \shape default is auto-appended by the compiler, e.g. small, large, z80, ds390 etc \end_layout \begin_layout Standard \noindent The install paths can still be changed during `make install' with e.g.: \end_layout \begin_layout LyX-Code make install prefix=$(HOME)/local/sdcc \end_layout \begin_layout Standard Of course this doesn't change the search paths compiled into the binaries. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Moreover the install path can be changed by defining DESTDIR \begin_inset Index idx status collapsed \begin_layout Plain Layout DESTDIR \end_layout \end_inset : \end_layout \begin_layout LyX-Code make install DESTDIR=$(HOME)/sdcc.rpm/ \end_layout \begin_layout Standard Please note that DESTDIR must have a trailing slash! \end_layout \begin_layout Section Search Paths \begin_inset CommandInset label LatexCommand label name "subsec:Search-Paths" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Search path \end_layout \end_inset \end_layout \begin_layout Standard Some search paths or parts of them are determined by configure variables (in \emph on italics \emph default , see section above). Further search paths are determined by environment variables during runtime. \begin_inset Newline newline \end_inset The paths searched when running the compiler are as follows (the first catch wins): \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset 1. Binary files (preprocessor, assembler and linker) \begin_inset Newline newline \end_inset \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout Search path \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout default \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Win32 builds \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME/ \emph on $PPREFIX2BIN_DIR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME/bin \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME \backslash bin \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Path of argv[0] (if available) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Path of argv[0] \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Path of argv[0] \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $PATH \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $PATH \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $PATH \end_layout \end_inset \end_inset \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard \noindent 2. Include files \begin_inset Newline newline \end_inset \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout # \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Search path \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout default \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Win32 builds \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -I dir \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -I dir \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -I dir \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 2 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_INCLUDE \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_INCLUDE \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_INCLUDE \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 3 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME/ \begin_inset Newline newline \end_inset \emph on $PREFIX2DATA_DIR/ \emph default \begin_inset Newline newline \end_inset \emph on $INCLUDE_DIR_SUFFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME/ \begin_inset Newline newline \end_inset share/sdcc/include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME \backslash include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 4 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout path(argv[0])/ \begin_inset Newline newline \end_inset \emph on $BIN2DATADIR/ \emph default \begin_inset Newline newline \end_inset \emph on $INCLUDE_DIR_SUFFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout path(argv[0])/../ \begin_inset Newline newline \end_inset sdcc/include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout path(argv[0]) \backslash .. \backslash include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 5 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $DATADIR/ \emph default \begin_inset Newline newline \end_inset \emph on $INCLUDE_DIR_SUFFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout /usr/local/share/ \begin_inset Newline newline \end_inset sdcc/include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout (not on Win32) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 6 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME/ \begin_inset Newline newline \end_inset \emph on $PREFIX2DATA_DIR/ \emph default \begin_inset Newline newline \end_inset \emph on non-free/ \emph default \begin_inset Newline newline \end_inset \emph on $INCLUDE_DIR_SUFFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME/share/ \begin_inset Newline newline \end_inset sdcc/non-free/include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME \backslash non-free \backslash include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 7 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout path(argv[0])/ \begin_inset Newline newline \end_inset \emph on $BIN2DATADIR/ \emph default \begin_inset Newline newline \end_inset \emph on non-free/ \emph default \begin_inset Newline newline \end_inset \emph on $INCLUDE_DIR_SUFFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout path(argv[0])/../ \begin_inset Newline newline \end_inset sdcc/non-free/include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout path(argv[0]) \backslash .. \backslash non-free \backslash include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 8 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $DATADIR/ \emph default \begin_inset Newline newline \end_inset \emph on non-free/ \emph default \begin_inset Newline newline \end_inset \emph on $INCLUDE_DIR_SUFFIX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout /usr/local/share/ \begin_inset Newline newline \end_inset sdcc/non-free/include \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout (not on Win32) \end_layout \end_inset \end_inset \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard \noindent The option - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -nostdinc disables all search paths except #1 and #2. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset 3. Library files \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard With the exception of \begin_inset Quotes sld \end_inset - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -L dir \begin_inset Quotes srd \end_inset the \shape italic model \shape default is auto-appended by the compiler (e.g. small, large, z80, ds390 etc.). \begin_inset Newline newline \end_inset \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout # \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Search path \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout default \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Win32 builds \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -L dir \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -L dir \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -L dir \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 2 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_LIB/ \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_LIB/ \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_LIB/ \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 3 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_LIB \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_LIB \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_LIB \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 4 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME/ \begin_inset Newline newline \end_inset \emph on $PREFIX2DATA_DIR/ \emph default \begin_inset Newline newline \end_inset \emph on $LIB_DIR_SUFFIX/ \emph default \begin_inset Newline newline \end_inset \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME/ \begin_inset Newline newline \end_inset share/sdcc/lib/< \emph on model> \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME \backslash \begin_inset Newline newline \end_inset lib \backslash \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 5 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout path(argv[0])/ \begin_inset Newline newline \end_inset \emph on $BIN2DATADIR/ \emph default \begin_inset Newline newline \end_inset \emph on $LIB_DIR_SUFFIX/ \emph default \begin_inset Newline newline \end_inset \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout path(argv[0])/../sdcc/ \begin_inset Newline newline \end_inset lib/ \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout path(argv[0]) \backslash \begin_inset Newline newline \end_inset .. \backslash lib \backslash \begin_inset Newline newline \end_inset \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 6 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $DATADIR/non-free/ \emph default \begin_inset Newline newline \end_inset \emph on $LIB_DIR_SUFFIX/ \emph default \begin_inset Newline newline \end_inset \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout /usr/local/share/sdcc/ \begin_inset Newline newline \end_inset lib/ \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout (not on Win32) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 7 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME/ \begin_inset Newline newline \end_inset \emph on $PREFIX2DATA_DIR/ \emph default \begin_inset Newline newline \end_inset \emph on non-free/ \emph default \begin_inset Newline newline \end_inset \emph on $LIB_DIR_SUFFIX/ \emph default \begin_inset Newline newline \end_inset \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME/share/sdcc/ \begin_inset Newline newline \end_inset non-free/lib/ \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout $SDCC_HOME \backslash \begin_inset Newline newline \end_inset lib \backslash non-free \emph on \backslash \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 8 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout path(argv[0])/ \begin_inset Newline newline \end_inset \emph on $BIN2DATADIR/ \emph default \begin_inset Newline newline \end_inset \emph on non-free/ \emph default \begin_inset Newline newline \end_inset \emph on $LIB_DIR_SUFFIX/ \emph default \begin_inset Newline newline \end_inset \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout path(argv[0])/../sdcc/ \begin_inset Newline newline \end_inset non-free/lib/ \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout path(argv[0]) \backslash .. \backslash \begin_inset Newline newline \end_inset lib \backslash non-free \emph on \backslash \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 9 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on $DATADIR/non-free/ \emph default \begin_inset Newline newline \end_inset \emph on $LIB_DIR_SUFFIX/ \emph default \begin_inset Newline newline \end_inset \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout /usr/local/share/sdcc/ \begin_inset Newline newline \end_inset non-free/lib/ \begin_inset Newline newline \end_inset \emph on \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout (not on Win32) \end_layout \end_inset \end_inset \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard \begin_inset Note Note status collapsed \begin_layout Plain Layout Don't delete any of the stray spaces in the table above without checking the HTML output (last line)! \end_layout \end_inset \end_layout \begin_layout Standard \begin_inset space ~ \end_inset \begin_inset Newline newline \end_inset The option - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -nostdlib disables all search paths except #1 and #2. \end_layout \begin_layout Section Building SDCC \begin_inset Index idx status collapsed \begin_layout Plain Layout Building SDCC \end_layout \end_inset \end_layout \begin_layout Subsection Building SDCC on Linux \begin_inset CommandInset label LatexCommand label name "subsec:Building-SDCC-on-Linux" \end_inset \end_layout \begin_layout Enumerate \series medium Download the source package \series default either from the SDCC Subversion repository or from snapshot builds \series medium , it will be named something like sdcc \series default -src \series medium -yyyymmdd-rrrr.t \series default ar. \series medium bz2 \series default \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/snap.php \end_layout \end_inset . \end_layout \begin_layout Enumerate \series medium Bring up a command line terminal, such as xterm. \end_layout \begin_layout Enumerate \series medium Unpack the file using a command like: \series default \family sans \series bold "tar -xvjf sdcc-src-yyyymmdd-rrrr.tar.bz2 \begin_inset Quotes srd \end_inset \family default \series medium , this will create a sub-directory called sdcc with all of the sources. \end_layout \begin_layout Enumerate Change directory into the main SDCC directory, for example type: \family sans \series bold "cd sdcc \series default ". \end_layout \begin_layout Enumerate \series medium Type \series default \family sans \series bold "./configure \family default \series default ". This configures the package for compilation on your system. When the treedec library is available, it should be found and used automaticall y (improving the compilation time / code quality trade-off). As of SDCC 3.7.0, the current develop branch from https://github.com/freetdi/tdlib is a suitable version of treedec. \end_layout \begin_layout Enumerate \series medium Type \series default \family sans \series bold "make \family default \series default " \series medium . \series default All of the source packages will compile, this can take a while. \end_layout \begin_layout Enumerate \series medium Type \series default \family sans \series bold "make install" \family default \series default as root \series medium . \series default This copies the binary executables, the include files, the libraries and the documentation to the install directories. Proceed with section \begin_inset CommandInset ref LatexCommand ref reference "sec:Testing-the-SDCC" \end_inset . \end_layout \begin_layout Subsection Building SDCC on Mac OS X \end_layout \begin_layout Standard Follow the instruction for Linux. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset On Mac OS X 10.2.x it was reported, that the default gcc (version 3.1 20020420 (prerelease)) fails to compile SDCC. Fortunately there's also gcc 2.9.x installed, which works fine. This compiler can be selected by running 'configure' with: \end_layout \begin_layout LyX-Code ./configure CC=gcc2 CXX=g++2 \end_layout \begin_layout Standard Universal (ppc and i386) binaries can be produced on Mac OS X 10.4.x with Xcode. Run 'configure' with: \end_layout \begin_layout LyX-Code ./configure \backslash \end_layout \begin_layout LyX-Code LDFLAGS="-Wl,-syslibroot,/Developer/SDKs/MacOSX10.4u.sdk -arch i386 -arch ppc" \backslash \end_layout \begin_layout LyX-Code CXXFLAGS = "-O2 -isysroot /Developer/SDKs/MacOSX10.4u.sdk -arch i386 -arch ppc" \backslash \end_layout \begin_layout LyX-Code CFLAGS = "-O2 -isysroot /Developer/SDKs/MacOSX10.4u.sdk -arch i386 -arch ppc" \end_layout \begin_layout Subsection Cross compiling SDCC on Linux for Windows \end_layout \begin_layout Standard With the Mingw32 gcc cross compiler it's easy to compile SDCC for Win32. See section 'Configure Options'. \end_layout \begin_layout Subsection Building SDCC using Cygwin and Mingw32 \end_layout \begin_layout Standard For building and installing a Cygwin executable follow the instructions for Linux. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset On Cygwin a \begin_inset Quotes sld \end_inset native \begin_inset Quotes srd \end_inset Win32-binary can be built, which will not need the Cygwin-DLL. For the necessary 'configure' options see section 'configure options' or the script 'sdcc/support/scripts/sdcc_cygwin_mingw32'. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset In order to install Cygwin on Windows download setup.exe from www.cygwin.com \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.cygwin.com/ \end_layout \end_inset . Run it, set the \begin_inset Quotes sld \end_inset default text file type \begin_inset Quotes srd \end_inset to \begin_inset Quotes sld \end_inset unix \begin_inset Quotes srd \end_inset and download/install at least the following packages. Some packages are selected by default, others will be automatically selected because of dependencies with the manually selected packages. Never deselect these packages! \end_layout \begin_layout Itemize flex \end_layout \begin_layout Itemize bison \end_layout \begin_layout Itemize gcc ; version 3.x is fine, no need to use the old 2.9x \end_layout \begin_layout Itemize binutils ; selected with gcc \end_layout \begin_layout Itemize make \end_layout \begin_layout Itemize libboost-dev \end_layout \begin_layout Itemize rxvt ; a nice console, which makes life much easier under windoze (see below) \end_layout \begin_layout Itemize man ; not really needed for building SDCC, but you'll miss it sooner or later \end_layout \begin_layout Itemize less ; not really needed for building SDCC, but you'll miss it sooner or later \end_layout \begin_layout Itemize svn ; only if you use Subversion access \end_layout \begin_layout Standard If you want to develop something you'll need: \end_layout \begin_layout Itemize python ; for the regression tests \end_layout \begin_layout Itemize gdb ; the gnu debugger, together with the nice GUI \begin_inset Quotes sld \end_inset insight \begin_inset Quotes srd \end_inset \end_layout \begin_layout Itemize openssh ; to access the CF or commit changes \end_layout \begin_layout Itemize autoconf and autoconf-devel ; if you want to fight with 'configure', don't use autoconf-stable! \end_layout \begin_layout Standard rxvt is a nice console with history. Replace in your cygwin.bat the line \end_layout \begin_layout LyX-Code bash - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -login -i \end_layout \begin_layout Standard with (one line): \end_layout \begin_layout LyX-Code rxvt -sl 1000 -fn "Lucida Console-12" -sr -cr red \end_layout \begin_layout LyX-Code -bg black -fg white -geometry 100x65 -e bash - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -login \end_layout \begin_layout Standard Text selected with the mouse is automatically copied to the clipboard, pasting works with shift-insert. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset The other good tip is to make sure you have no //c/-style paths anywhere, use /cygdrive/c/ instead. Using // invokes a network lookup which is very slow. If you think \begin_inset Quotes sld \end_inset cygdrive \begin_inset Quotes srd \end_inset is too long, you can change it with e.g. \end_layout \begin_layout LyX-Code mount -s -u -c /mnt \end_layout \begin_layout Standard SDCC sources use the unix line ending LF. Life is much easier, if you store the source tree on a drive which is mounted in binary mode. And use an editor which can handle LF-only line endings. Make sure not to commit files with windows line endings. The tabulator spacing \begin_inset Index idx status collapsed \begin_layout Plain Layout tabulator spacing (8 columns) \end_layout \end_inset used in the project is 8. Although a tabulator spacing of 8 is a sensible choice for programmers (it's a power of 2 and allows to display 8/16 bit signed variables without loosing columns) the plan is to move towards using only spaces in the source. \end_layout \begin_layout Subsection Building SDCC Using Microsoft Visual C++ 2010 (MSVC) \end_layout \begin_layout Standard \series medium Download the source package \series default either from the SDCC Subversion repository or from the snapshot builds \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/snap.php \end_layout \end_inset \series medium , it will be named something like sdcc \series default -src \series medium -yyyymmdd-rrrr.tar.bz2. \series default SDCC is distributed with all the project, solution and other files you need to build it using Visual C++ 2010 (except for ucSim). The solution name is 'sdcc.sln'. Please note that as it is now, all the executables are created in a folder called sdcc \backslash bin_vc. Once built you need to copy the executables from sdcc \backslash bin_vc to sdcc \backslash bin before running SDCC. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Apart from the SDCC sources you also need to have the BOOST libraries installed for MSVC. Get it here \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.boost.org/ \end_layout \end_inset \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset In order to build SDCC with MSVC you need win32 executables of bison.exe, flex.exe, and gawk.exe. One good place to get them is here \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://unxutils.sourceforge.net \end_layout \end_inset \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset If UnxUtils didn't work well, \begin_inset Index idx status collapsed \begin_layout Plain Layout msys \end_layout \end_inset msys ( \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.mingw.org/wiki/msys \end_layout \end_inset ) or msys2 \begin_inset Index idx status collapsed \begin_layout Plain Layout msys2 \end_layout \end_inset ( \begin_inset Flex URL status collapsed \begin_layout Plain Layout https://msys2.github.io \end_layout \end_inset ) can be an alternative. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Download the file UnxUtils \begin_inset Index idx status collapsed \begin_layout Plain Layout UnxUtils \end_layout \end_inset .zip. Now you have to install the utilities and setup MSVC so it can locate the required programs. Here there are two alternatives (choose one!): \end_layout \begin_layout Enumerate The easy way: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset a) Extract UnxUtils.zip to your C: \backslash hard disk PRESERVING the original paths, otherwise bison won't work. (If you are using WinZip make certain that 'Use folder names' is selected) \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset b) Add 'C: \backslash user \backslash local \backslash wbin' to VC++ Directories / Executable Directories. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset (As a side effect, you get a bunch of Unix utilities that could be useful, such as diff and patch.) \end_layout \begin_layout Enumerate A more compact way: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset This one avoids extracting a bunch of files you may not use, but requires some extra work: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset a) Create a directory were to put the tools needed, or use a directory already present. Say for example 'C: \backslash util'. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset b) Extract 'bison.exe', 'bison.hairy', 'bison.simple', 'flex.exe', and gawk.exe to such directory WITHOUT preserving the original paths. (If you are using WinZip make certain that 'Use folder names' is not selected) \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset c) Rename bison.exe to '_bison.exe'. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset d) Create a batch file 'bison.bat' in 'C: \backslash util \backslash ' and add these lines: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset set BISON_SIMPLE=C: \backslash util \backslash bison.simple \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset set BISON_HAIRY=C: \backslash util \backslash bison.hairy \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _bison %1 %2 %3 %4 %5 %6 %7 %8 %9 \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Steps 'c' and 'd' are needed because bison requires by default that the files 'bison.simple' and 'bison.hairy' reside in some weird Unix directory, '/usr/local/share/' I think. So it is necessary to tell bison where those files are located if they are not in such directory. That is the function of the environment variables BISON_SIMPLE and BISON_HAIRY. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset e) Add 'C: \backslash util' to VC++ Directories / Executable Directories. Note that you can use any other path instead of 'C: \backslash util', even the path where the Visual C++ tools are, probably: 'C: \backslash Program Files \backslash Microsoft Visual Studio \backslash Common \backslash Tools'. So you don't have to execute step 'e' :) \end_layout \begin_layout Standard That is it. Open 'sdcc.sln' in Visual Studio, click 'build all', when it finishes copy the executables from sdcc \backslash bin_vc to sdcc \backslash bin, and you can compile using SDCC. \end_layout \begin_layout Subsection Windows Install Using a ZIP Package \end_layout \begin_layout Enumerate Download the binary zip package from \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sf.net/snap.php \end_layout \end_inset and unpack it using your favorite unpacking tool (gunzip, WinZip, etc). This should unpack to a group of sub-directories. An example directory structure after unpacking the mingw32 package is: C: \backslash sdcc \backslash bin for the executables, C: \backslash sdcc \backslash include and C: \backslash sdcc \backslash lib for the include and libraries. \end_layout \begin_layout Enumerate Adjust your environment variable PATH to include the location of the bin directory or start sdcc using the full path. \end_layout \begin_layout Subsection Windows Install Using the Setup Program \begin_inset CommandInset label LatexCommand label name "subsec:Windows-Install" \end_inset \end_layout \begin_layout Standard Download the setup program \emph on sdcc-x.y.z-setup.exe \emph default for an official release from \begin_inset Newline newline \end_inset \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/projects/sdcc/files/ \end_layout \end_inset or a setup program for one of the snapshots \emph on sdcc-yyyymmdd-xxxx-setup.exe \emph default from \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/snap.php \end_layout \end_inset and execute it. A windows typical installer will guide you through the installation process. \end_layout \begin_layout Subsection VPATH \begin_inset Index idx status collapsed \begin_layout Plain Layout VPATH \end_layout \end_inset feature \end_layout \begin_layout Standard SDCC supports the VPATH feature provided by configure and make. It allows to separate the source and build trees. Here's an example: \end_layout \begin_layout Standard \family typewriter cd ~ \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset # cd $HOME \end_layout \begin_layout Standard \family typewriter tar -xjf sdcc-src-yyyymmdd-rrrr.tar.bz2 \begin_inset space ~ \end_inset # extract source to directory sdcc \end_layout \begin_layout Standard \family typewriter mkdir sdcc.build \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset # put output in sdcc.build \end_layout \begin_layout Standard \family typewriter cd sdcc.build \end_layout \begin_layout Standard \family typewriter ../sdcc/configure \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset # configure is doing all the magic! \end_layout \begin_layout Standard \family typewriter make \end_layout \begin_layout Standard \noindent That's it! \series bold configure \series default will create the directory tree will all the necessary Makefiles in ~/sdcc.build. It automagically computes the variables srcdir, top_srcdir and top_buildir for each directory. After running \series bold make \series default the generated files will be in ~/sdcc.build, while the source files stay in ~/sdcc. \begin_inset Newline newline \end_inset This is not only usefull for building different binaries, e.g. when cross compiling. It also gives you a much better overview in the source tree when all the generated files are not scattered between the source files. And the best thing is: if you want to change a file you can leave the original file untouched in the source directory. Simply copy it to the build directory, edit it, enter `make clean', `rm Makefile.dep' and `make'. \series bold make \series default will do the rest for you! \end_layout \begin_layout Section Building the Documentation \end_layout \begin_layout Standard Add - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -enable-doc to the configure arguments to build the documentation together with all the other stuff. You will need several tools (\SpecialChar LyX , \SpecialChar LaTeX , \SpecialChar LaTeX 2HTML, pdflatex, dvipdf, dvips and makeindex) to get the job done. Another possibility is to change to the doc directory and to type \family sans \series bold \begin_inset Quotes srd \end_inset make \begin_inset Quotes srd \end_inset \family default \series default there. You're invited to make changes and additions to this manual (sdcc/doc/sdccman.ly x). Using \SpecialChar LyX \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.lyx.org \end_layout \end_inset as editor is straightforward. Prebuilt documentation is available from \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/snap.php \end_layout \end_inset . \end_layout \begin_layout Section Reading the Documentation \begin_inset Index idx status collapsed \begin_layout Plain Layout Documentation \end_layout \end_inset \end_layout \begin_layout Standard Currently reading the document in pdf format is recommended, as for unknown reason the hyperlinks are working there whereas in the html version they are not \begin_inset Foot status collapsed \begin_layout Plain Layout If you should know why please drop us a note \end_layout \end_inset . \begin_inset Newline newline \end_inset You'll find the pdf version \begin_inset Index idx status collapsed \begin_layout Plain Layout PDF version of this document \end_layout \end_inset at \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/doc/sdccman.pdf \end_layout \end_inset . \begin_inset Newline newline \end_inset This documentation is in some aspects different from a commercial documentation: \end_layout \begin_layout Itemize It tries to document SDCC for several processor architectures in one document (commercially these probably would be separate documents/products). This document \begin_inset Index idx status collapsed \begin_layout Plain Layout Status of documentation \end_layout \end_inset currently matches SDCC for mcs51 and DS390 best and does give too few informati on about f.e. Z80, PIC14, PIC16 and HC08. \end_layout \begin_layout Itemize There are many references pointing away from this documentation. Don't let this distract you. If there f.e. was a reference like \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.opencores.org \end_layout \end_inset together with a statement \begin_inset Quotes sld \end_inset some processors which are targeted by SDCC can be implemented in a \emph on f \emph default ield \emph on p \emph default rogrammable \emph on g \emph default ate \emph on a \emph default rray \begin_inset Index idx status collapsed \begin_layout Plain Layout FPGA (field programmable gate array) \end_layout \end_inset \begin_inset Quotes srd \end_inset or \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/projects/fpgac/ \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout FpgaC ((subset of) C to FPGA compiler) \end_layout \end_inset \begin_inset Quotes sld \end_inset have you ever heard of an open source compiler that compiles a subset of C for an FPGA? \begin_inset Quotes srd \end_inset we expect you to have a quick look there and come back. If you read this you are on the right track. \end_layout \begin_layout Itemize Some sections attribute more space to problems, restrictions and warnings than to the solution. \end_layout \begin_layout Itemize The installation section and the section about the debugger is intimidating. \end_layout \begin_layout Itemize There are still lots of typos and there are more different writing styles than pictures. \end_layout \begin_layout Section Testing the SDCC Compiler \begin_inset CommandInset label LatexCommand label name "sec:Testing-the-SDCC" \end_inset \end_layout \begin_layout Standard The first thing you should do after installing your SDCC compiler is to see if it runs. Type \family sans \series bold "sdcc - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -version" \begin_inset Index idx status collapsed \begin_layout Plain Layout version \end_layout \end_inset \family default \series default at the prompt, and the program should run and output its version like: \begin_inset Newline newline \end_inset \family typewriter SDCC : mcs51/z80/avr/ds390/pic16/pic14/ds400/hc08 2.5.6 #4169 (May 8 2006) (UNIX) \end_layout \begin_layout Standard If it doesn't run, or gives a message about not finding sdcc program, then you need to check over your installation. Make sure that the sdcc bin directory is in your executable search path defined by the PATH environment setting ( \series medium see \series default section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Install-Trouble-shooting" \end_inset \begin_inset space ~ \end_inset \series medium Install trouble-shooting for suggestions \series default ). Make sure that the sdcc program is in the bin folder, if not perhaps something did not install correctly. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \series medium SDCC \series default is commonly installed as described in section \begin_inset Quotes sld \end_inset Install and search paths \begin_inset Quotes srd \end_inset . \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \series medium Make sure the compiler works on a very simple example. Type in the following test.c program using your favorite \series default ASCII \series medium editor: \end_layout \begin_layout Verse \family typewriter char test; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset void main(void) { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset test=0; \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard \series medium Compile this using the following command: \series default \family sans \series bold "sdcc -c test.c". \family default \series default \series medium If all goes well, the compiler will generate a test.asm and test.rel file. Congratulations, you've just compiled your first program with SDCC. We used the -c option to tell SDCC not to link the generated code, just to keep things simple for this step. \series default \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \series medium The next step is to try it with the linker. Type in \series default \family sans \series bold "sdcc test.c \family default \series default " \series medium . If all goes well the compiler will link with the libraries and produce a test.ihx output file. If this step fails \series default \series medium (no test.ihx, and the linker generates warnings), then the problem is most likely that \series default SDCC \series medium cannot find the \series default / \series medium usr/local/share/sdcc/lib directory \series default \series medium (see \series default section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Install-Trouble-shooting" \end_inset \begin_inset space ~ \end_inset \series medium Install trouble-shooting for suggestions). \series default \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \series medium The final test is to ensure \series default SDCC \series medium can use the \series default standard \series medium header files and libraries. Edit test.c and change it to the following: \end_layout \begin_layout Verse \family typewriter #include \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset char str1[10]; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset void main(void) { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset strcpy(str1, "testing"); \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard \series medium Compile this by typing \series default \family sans \series bold "sdcc test.c" \family default \series medium . This should generate a test.ihx output file, and it should give no warnings such as not finding the string.h file. If it cannot find the string.h file, then the problem is that \series default SDCC \series medium cannot find the /usr/local/share/sdcc/include directory \series default \series medium (see the \series default section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Install-Trouble-shooting" \end_inset \begin_inset space ~ \end_inset \series medium Install trouble-shooting section for suggestions). \series default Use option \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -print-search-dirs \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -print-search-dirs \end_layout \end_inset to find exactly where SDCC is looking for the include and lib files. \end_layout \begin_layout Section Install Trouble-shooting \begin_inset CommandInset label LatexCommand label name "subsec:Install-Trouble-shooting" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Install trouble-shooting \end_layout \end_inset \end_layout \begin_layout Subsection If SDCC does not build correctly \end_layout \begin_layout Standard A thing to try is starting from scratch by unpacking the .tgz source package again in an empty directory. Configure it like: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family sans \series bold ./configure 2>&1 | tee configure.log \family default \series default \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset and build it like: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family sans \series bold make 2>&1 | tee make.log \family default \series default \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset If anything goes wrong, you can review the log files to locate the problem. Or a relevant part of this can be attached to an email that could be helpful when requesting help from the mailing list. \end_layout \begin_layout Subsection What the \begin_inset Quotes sld \end_inset ./configure \begin_inset Quotes srd \end_inset does \end_layout \begin_layout Standard The \begin_inset Quotes sld \end_inset ./configure \begin_inset Quotes srd \end_inset command is a script that analyzes your system and performs some configuration to ensure the source package compiles on your system. It will take a few minutes to run, and will compile a few tests to determine what compiler features are installed. \end_layout \begin_layout Subsection What the \begin_inset Quotes sld \end_inset make \begin_inset Quotes srd \end_inset does \end_layout \begin_layout Standard This runs the GNU make tool, which automatically compiles all the source packages into the final installed binary executables. \end_layout \begin_layout Subsection What the \begin_inset Quotes sld \end_inset make install \begin_inset Quotes erd \end_inset command does. \end_layout \begin_layout Standard This will install the compiler, other executables libraries and include files into the appropriate directories. See sections \begin_inset CommandInset ref LatexCommand ref reference "subsec:Install-paths" \end_inset , \begin_inset space ~ \end_inset \begin_inset CommandInset ref LatexCommand ref reference "subsec:Search-Paths" \end_inset \begin_inset space ~ \end_inset about install and search paths. \begin_inset Newline newline \end_inset On most systems you will need super-user privileges to do this. \end_layout \begin_layout Section Components of SDCC \end_layout \begin_layout Standard SDCC is not just a compiler, but a collection of tools by various developers. These include linkers, assemblers, simulators and other components. Here is a summary of some of the components. Note that the included simulator and assembler have separate documentation which you can find in the source package in their respective directories. As SDCC grows to include support for other processors, other packages from various developers are included and may have their own sets of documentation. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset You might want to look at the files which are installed in . At the time of this writing, we find the following programs for gcc-builds: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset In /bin: \end_layout \begin_layout Itemize sdcc - The compiler. \end_layout \begin_layout Itemize sdcpp - The C preprocessor. \end_layout \begin_layout Itemize sdas8051 - The assembler for 8051 type processors. \end_layout \begin_layout Itemize sdas390 - The assembler for DS80C390 processor. \end_layout \begin_layout Itemize sdasz80 \series bold , \series default sdasgb - The Z80 and GameBoy Z80 assemblers. \end_layout \begin_layout Itemize sdas6808 - The 6808 assembler. \end_layout \begin_layout Itemize sdasstm8 - The STM8 assembler. \end_layout \begin_layout Itemize sdld -The linker for 8051 and STM8 type processors. \end_layout \begin_layout Itemize sdldz80 \series bold , \series default sdldgb - The Z80 and GameBoy Z80 linkers. \end_layout \begin_layout Itemize sdld6808 - The 6808 linker. \end_layout \begin_layout Itemize s51 - The ucSim 8051 simulator. \end_layout \begin_layout Itemize sz80 - The ucSim Z80 simulator. \end_layout \begin_layout Itemize shc08 - The ucSim 6808 simulator. \end_layout \begin_layout Itemize sstm8 - The ucSim STM8 simulator. \end_layout \begin_layout Itemize sdcdb - The source debugger. \end_layout \begin_layout Itemize sdar, sdranlib, sdnm, sdobjcopy - The sdcc archive managing and indexing utilites. \end_layout \begin_layout Itemize packihx - A tool to pack (compress) Intel hex files. \end_layout \begin_layout Itemize makebin - A tool to convert Intel Hex file to a binary and GameBoy binary image file format. \end_layout \begin_layout Standard In /share/sdcc/include \end_layout \begin_layout Itemize the include files \end_layout \begin_layout Standard In /share/sdcc/non-free/include \end_layout \begin_layout Itemize the non-free include files \end_layout \begin_layout Standard In /share/sdcc/lib \end_layout \begin_layout Itemize the src and target subdirectories with the precompiled relocatables. \end_layout \begin_layout Standard In /share/sdcc/non-free/lib \end_layout \begin_layout Itemize the src and target subdirectories with the non-free precompiled relocatables. \end_layout \begin_layout Standard In /share/sdcc/doc \end_layout \begin_layout Itemize the documentation \end_layout \begin_layout Subsection sdcc - The Compiler \end_layout \begin_layout Standard This is the actual compiler, it in turn uses the c-preprocessor and invokes the assembler and linkage editor. \end_layout \begin_layout Subsection sdcpp - The C-Preprocessor \begin_inset Index idx status collapsed \begin_layout Plain Layout Preprocessor \end_layout \end_inset \end_layout \begin_layout Standard The preprocessor \begin_inset Index idx status collapsed \begin_layout Plain Layout sdcpp (preprocessor) \end_layout \end_inset is a modified version of the GNU cpp \begin_inset Index idx status collapsed \begin_layout Plain Layout cpp|see \begin_inset ERT status collapsed \begin_layout Plain Layout { \end_layout \end_inset sdcpp \begin_inset ERT status collapsed \begin_layout Plain Layout } \end_layout \end_inset \end_layout \end_inset preprocessor \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://gcc.gnu.org/ \end_layout \end_inset . The C preprocessor is used to pull in #include sources, process #ifdef statements, #defines and so on. \end_layout \begin_layout Subsection sdas, sdld - The Assemblers and Linkage Editors \end_layout \begin_layout Standard This is a set of retargettable assemblers and linkage editors, which was developed by Alan Baldwin. John Hartman created the version for 8051, and I (Sandeep) have made some enhancements and bug fixes for it to work properly with SDCC. \end_layout \begin_layout Standard SDCC used an about 1998 branch of asxxxx version 2.0 which unfortunately is not compatible with the more advanced (f.e. macros, more targets) ASxxxx Cross Assemblers nowadays available from Alan Baldwin \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://shop-pdp.kent.edu/ \end_layout \end_inset . In 2009 Alan made his ASxxxx Cross Assemblers version 5.0 available under the GPL license (GPLv3 or later), so a reunion is now a work in progress. Thanks Alan! \end_layout \begin_layout Subsection s51, sz80, shc08, sstm8 - The Simulators \end_layout \begin_layout Standard s51 \begin_inset Index idx status collapsed \begin_layout Plain Layout s51 (simulator) \end_layout \end_inset , sz80 \begin_inset Index idx status collapsed \begin_layout Plain Layout sz80 (simulator) \end_layout \end_inset shc08 \begin_inset Index idx status collapsed \begin_layout Plain Layout shc08 (simulator) \end_layout \end_inset and sstm8 \begin_inset Index idx status collapsed \begin_layout Plain Layout sstm8 (simulator) \end_layout \end_inset are free open source simulators developed by Daniel Drotos. The simulators are built as part of the build process. For more information visit Daniel's web site at: \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://mazsola.iit.uni-miskolc.hu/~drdani/embedded/s51 \end_layout \end_inset . It currently supports the core mcs51, the Dallas DS80C390, the Phillips XA51 family, the Z80, 6808 and the STM8. \end_layout \begin_layout Subsection sdcdb - Source Level Debugger \end_layout \begin_layout Standard SDCDB \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCDB (debugger) \end_layout \end_inset is the companion source level debugger. More about SDCDB in section \begin_inset CommandInset ref LatexCommand ref reference "cha:Debugging-with-SDCDB" \end_inset . The current version of the debugger uses Daniel's Simulator S51 \begin_inset Index idx status collapsed \begin_layout Plain Layout s51 (simulator) \end_layout \end_inset , but can be easily changed to use other simulators. \end_layout \begin_layout Chapter Using SDCC \end_layout \begin_layout Section Standard-Compliance \begin_inset Index idx status collapsed \begin_layout Plain Layout Standard-compliance \end_layout \end_inset \begin_inset CommandInset label LatexCommand label name "subsec:Standard-Compliance" \end_inset \end_layout \begin_layout Standard SDCC aims to be a conforming freestanding implementation of the C programming language. \end_layout \begin_layout Subsection ISO C90 and ANSI C89 \end_layout \begin_layout Standard Use \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c89 \begin_inset Index idx status open \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c89 \end_layout \end_inset \series default to compile in this mode. \end_layout \begin_layout Standard The latest publicly available version of the standard \emph on ISO/IEC 9899 - Programming languages - C \emph default should be available at: \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.open-std.org/jtc1/sc22/wg14/www/standards.html#9899 \end_layout \end_inset . \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard Deviations from standard compliance: \end_layout \begin_layout Itemize structures \begin_inset Index idx status collapsed \begin_layout Plain Layout struct \end_layout \end_inset and unions \begin_inset Index idx status collapsed \begin_layout Plain Layout union \end_layout \end_inset cannot be passed as function parameters and cannot be a return value \begin_inset Index idx status collapsed \begin_layout Plain Layout return value \end_layout \end_inset from a function, e.g.: \begin_inset Separator latexpar \end_inset \end_layout \begin_deeper \begin_layout Verse \family typewriter struct s { ... }; \begin_inset Newline newline \end_inset \series bold struct \family default \series default \family typewriter s foo1 ( \series bold struct \family default \series default \family typewriter s parms) /* invalid in SDCC although allowed in ANSI */ \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset struct s rets; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset return rets; /* is invalid in SDCC although allowed in ANSI */ \begin_inset Newline newline \end_inset } \end_layout \end_deeper \begin_layout Itemize initialization of structure arrays must be fully braced. \begin_inset Separator latexpar \end_inset \end_layout \begin_deeper \begin_layout Verse \family typewriter struct s { char x } a[] = {1, 2}; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* invalid in SDCC */ \begin_inset Newline newline \end_inset struct s { char x } a[] = {{1}, {2}}; /* OK */ \end_layout \end_deeper \begin_layout Itemize 'double \begin_inset Index idx status collapsed \begin_layout Plain Layout double (not supported) \end_layout \end_inset ' precision floating point \begin_inset Index idx status collapsed \begin_layout Plain Layout Floating point support \end_layout \end_inset not supported. Instead a warning is emitted, and float is used instead. long double is not supported. \end_layout \begin_layout Itemize Old K&R style \begin_inset Index idx status collapsed \begin_layout Plain Layout K \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash & \end_layout \end_inset R style \end_layout \end_inset function declarations are not supported. \begin_inset Separator latexpar \end_inset \end_layout \begin_deeper \begin_layout Verse \family typewriter foo(i,j) /* this old style of function declarations */ \begin_inset Newline newline \end_inset int i,j; /* is valid in ANSI but not valid in SDCC */ \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset } \end_layout \end_deeper \begin_layout Standard Some features of this standard are not supported in some ports: \end_layout \begin_layout Itemize Functions are not reentrant unless explicitly declared as such or \series bold \begin_inset Flex Code status open \begin_layout Plain Layout \series bold -- \series default stack-auto \end_layout \end_inset \series default is specified in the mcs51, ds390, hc08 and s08 ports. \end_layout \begin_layout Subsection ISO C95 \end_layout \begin_layout Standard Use \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c95 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c95 \end_layout \end_inset \series default to compile in this mode. \end_layout \begin_layout Standard Except for the issues mentioned in the section above, this standard is supported. \end_layout \begin_layout Subsection ISO C99 \end_layout \begin_layout Standard Use \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c99 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c99 \end_layout \end_inset \series default to compile in this mode. \end_layout \begin_layout Standard In addition to what is mentioned in the section above, the following features of this standard are not supported by SDCC: \end_layout \begin_layout Itemize Compound literals. \end_layout \begin_layout Itemize Variable-length arrays. \end_layout \begin_layout Standard Some features of this standard are not supported in some ports: \end_layout \begin_layout Itemize There is no support for data types long long, unsigned long long, int_fast64_t, int_least64_t, int64_t, uint_fast64_t, uint_least64_t, uint64_t in the pic14 and pic16 ports. \end_layout \begin_layout Subsection ISO C11 and ISO C17 \end_layout \begin_layout Standard Use \series bold - \begin_inset ERT status open \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c11 \begin_inset Index idx status open \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c11 \end_layout \end_inset \series default to compile in this mode. \end_layout \begin_layout Standard Except for the issues mentioned in the section above, this standard is supported. \end_layout \begin_layout Subsection ISO C2X \end_layout \begin_layout Standard Use \series bold - \begin_inset ERT status open \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c2x \begin_inset Index idx status open \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c2x \end_layout \end_inset \series default to compile in this mode. \end_layout \begin_layout Standard Standard and support are still quite incomplete. \end_layout \begin_layout Subsection Embedded C \end_layout \begin_layout Standard SDCC supports named address spaces. The support for fixed-point math in SDCC is inconsistent with the standard. Other parts of the standard are not supported. \end_layout \begin_layout Section Compiling \end_layout \begin_layout Subsection Single Source File Projects \end_layout \begin_layout Standard For single source file 8051 projects the process is very simple. Compile your programs with the following command \family sans \series bold "sdcc sourcefile.c". \family default \series default This will compile, assemble and link your source file. Output files are as follows: \end_layout \begin_layout Itemize sourcefile.asm \begin_inset Index idx status collapsed \begin_layout Plain Layout .asm \end_layout \end_inset - Assembler source \begin_inset Index idx status collapsed \begin_layout Plain Layout Assembler source \end_layout \end_inset file created by the compiler \end_layout \begin_layout Itemize sourcefile.lst \begin_inset Index idx status collapsed \begin_layout Plain Layout .lst \end_layout \end_inset - Assembler listing \begin_inset Index idx status collapsed \begin_layout Plain Layout Assembler listing \end_layout \end_inset file created by the Assembler \end_layout \begin_layout Itemize sourcefile.rst \begin_inset Index idx status collapsed \begin_layout Plain Layout .rst \end_layout \end_inset - Assembler listing \begin_inset Index idx status collapsed \begin_layout Plain Layout Assembler listing \end_layout \end_inset file updated with linkedit information, created by linkage editor \end_layout \begin_layout Itemize sourcefile.sym \begin_inset Index idx status collapsed \begin_layout Plain Layout .sym \end_layout \end_inset - symbol listing \begin_inset Index idx status collapsed \begin_layout Plain Layout Symbol listing \end_layout \end_inset for the sourcefile, created by the assembler \end_layout \begin_layout Itemize sourcefile.rel \begin_inset Index idx status collapsed \begin_layout Plain Layout .rel \end_layout \end_inset - Object file \begin_inset Index idx status collapsed \begin_layout Plain Layout Object file \end_layout \end_inset created by the assembler, input to Linkage editor \end_layout \begin_layout Itemize sourcefile.map \begin_inset Index idx status collapsed \begin_layout Plain Layout .map \end_layout \end_inset - The memory map \begin_inset Index idx status collapsed \begin_layout Plain Layout Memory map \end_layout \end_inset for the load module, created by the Linker \end_layout \begin_layout Itemize sourcefile.mem \begin_inset Index idx status collapsed \begin_layout Plain Layout .mem \end_layout \end_inset - A file with a summary of the memory usage \end_layout \begin_layout Itemize sourcefile.ihx \begin_inset Index idx status collapsed \begin_layout Plain Layout .ihx \end_layout \end_inset - The load module in Intel hex format \begin_inset Index idx status collapsed \begin_layout Plain Layout Intel hex format \end_layout \end_inset (you can select the Motorola S19 format \begin_inset Index idx status collapsed \begin_layout Plain Layout Motorola S19 format \end_layout \end_inset with - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -out-fmt-s19 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -out-fmt-s19 \end_layout \end_inset . If you need another format you might want to use \family sans \shape italic objdump \family default \shape default \begin_inset Index idx status collapsed \begin_layout Plain Layout objdump (tool) \end_layout \end_inset or \family sans \shape italic srecord \family default \shape default \begin_inset Index idx status collapsed \begin_layout Plain Layout srecord (bin, hex, ... tool) \end_layout \end_inset \begin_inset Note Note status collapsed \begin_layout Plain Layout hyperlinks needed \end_layout \end_inset - see also section \begin_inset CommandInset ref LatexCommand vref reference "subsec:Postprocessing-the-Intel" \end_inset ). Both formats are documented in the documentation of srecord \begin_inset Index idx status collapsed \begin_layout Plain Layout srecord (bin, hex, ... tool) \end_layout \end_inset \end_layout \begin_layout Itemize sourcefile.adb \begin_inset Index idx status collapsed \begin_layout Plain Layout .adb \end_layout \end_inset - An intermediate file containing debug information needed to create the .cdb file (with - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug \end_layout \end_inset ) \end_layout \begin_layout Itemize sourcefile.cdb \begin_inset Index idx status collapsed \begin_layout Plain Layout .cdb \end_layout \end_inset - An optional file (with - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug) containing debug information. The format is documented in cdbfileformat.pdf \end_layout \begin_layout Itemize sourcefile.omf \begin_inset Index idx status collapsed \begin_layout Plain Layout .omf \end_layout \end_inset - An optional AOMF or AOMF51 \begin_inset Index idx status collapsed \begin_layout Plain Layout AOMF, AOMF51 \end_layout \end_inset \begin_inset CommandInset label LatexCommand label name "OMF file" \end_inset file containing debug information (generated with option - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug). The (Intel) \emph on a \emph default bsolute \emph on o \emph default bject \emph on m \emph default odule \emph on f \emph default ormat is a subformat of the OMF51 format and is commonly used by third party tools (debuggers \begin_inset Index idx status collapsed \begin_layout Plain Layout Debugger \end_layout \end_inset , simulators, emulators). \end_layout \begin_layout Itemize sourcefile.dump* \begin_inset Index idx status collapsed \begin_layout Plain Layout .dump* \end_layout \end_inset - Dump file to debug the compiler it self (generated with option - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -dumpall) (see section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Intermediate-Dump-Options" \end_inset \begin_inset space ~ \end_inset and section \begin_inset CommandInset ref LatexCommand ref reference "subsec:The-anatomy-of" \end_inset \begin_inset space ~ \end_inset \begin_inset Quotes sld \end_inset Anatomy of the compiler \begin_inset Quotes srd \end_inset ). \end_layout \begin_layout Subsection Postprocessing the Intel Hex \begin_inset Index idx status collapsed \begin_layout Plain Layout Intel hex format \end_layout \end_inset file \begin_inset CommandInset label LatexCommand label name "subsec:Postprocessing-the-Intel" \end_inset \end_layout \begin_layout Standard In most cases this won't be needed but the Intel Hex file \begin_inset Index idx status collapsed \begin_layout Plain Layout .ihx \end_layout \end_inset which is generated by SDCC might include lines of varying length and the addresses within the file are not guaranteed to be strictly ascending. If your toolchain or a bootloader does not like this you can use the tool \family typewriter packihx \family default \begin_inset Index idx status collapsed \begin_layout Plain Layout packihx (tool) \end_layout \end_inset which is part of the SDCC distribution: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family sans \series bold packihx sourcefile.ihx >sourcefile.hex \family default \series default \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset The separately available \emph on srecord \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout srecord (bin, hex, ... tool) \end_layout \end_inset package additionally allows to set undefined locations to a predefined value, to insert checksums \begin_inset Index idx status collapsed \begin_layout Plain Layout checksum \end_layout \end_inset of various flavours (crc, add, xor) and to perform other manipulations (convert, split, crop, offset, ...). \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family sans \series bold srec_cat \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sourcefile.ihx -intel \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset -o sourcefile.hex -intel \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family default \series default An example for a more complex command line \begin_inset Foot status collapsed \begin_layout Plain Layout the command backfills \begin_inset Index idx status collapsed \begin_layout Plain Layout backfill unused memory \end_layout \end_inset unused memory with 0x12 and the overall 16 bit sum of the complete 64 kByte block is zero. If the program counter on an mcs51 runs wild the backfill pattern 0x12 will be interpreted as an \family typewriter lcall \family default to address \family typewriter 0x1212 \family default (where an emergency routine could sit). \end_layout \end_inset could look like: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family sans \series bold \size footnotesize srec_cat \begin_inset space ~ \end_inset sourcefile.ihx -intel \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset -fill 0x12 0x0000 0xfffe \begin_inset space ~ \end_inset -little-endian-checksum-negative 0xfffe 0x02 0x02 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset -o sourcefile.hex -intel \size default \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family default \series default The srecord package is available at \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/projects/srecord/ \end_layout \end_inset . \end_layout \begin_layout Subsection Projects with Multiple Source Files \end_layout \begin_layout Standard SDCC can compile only ONE file at a time. Let us for example assume that you have a project containing the following files: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset foo1.c (contains some functions) \begin_inset Newline newline \end_inset foo2.c (contains some more functions) \begin_inset Newline newline \end_inset foomain.c (contains more functions and the function main) \begin_inset Newline newline \end_inset \size footnotesize \begin_inset Newline newline \end_inset \size default The first two files will need to be compiled separately with the commands: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family sans \series bold sdcc \begin_inset space ~ \end_inset -c \begin_inset space ~ \end_inset foo1.c \family default \series default \size footnotesize \begin_inset Newline newline \end_inset \family sans \series bold \size default sdcc \begin_inset space ~ \end_inset -c \begin_inset space ~ \end_inset foo2.c \family default \series default \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Then compile the source file containing the \emph on main() \emph default function and link \begin_inset Index idx status collapsed \begin_layout Plain Layout Linker \end_layout \end_inset the files together with the following command: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family sans \series bold sdcc \begin_inset space ~ \end_inset foomain.c \begin_inset space ~ \end_inset foo1.rel \begin_inset space ~ \end_inset foo2.rel \family default \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout .rel \end_layout \end_inset \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Alternatively, \emph on foomain.c \emph default can be separately compiled as well: \family sans \series bold \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset sdcc \begin_inset space ~ \end_inset -c \begin_inset space ~ \end_inset foomain.c \begin_inset Newline newline \end_inset sdcc foomain.rel foo1.rel foo2.rel \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family default \series default The file containing the \emph on main() \emph default function \noun on must \noun default be the \noun on first \noun default file specified in the command line, since the linkage editor processes file in the order they are presented to it. The linker is invoked from SDCC using a script file with extension .lnk \begin_inset Index idx status collapsed \begin_layout Plain Layout .lnk \end_layout \end_inset . You can view this file to troubleshoot linking problems such as those arising from missing libraries. \end_layout \begin_layout Subsection Projects with Additional Libraries \begin_inset Index idx status collapsed \begin_layout Plain Layout Libraries \end_layout \end_inset \end_layout \begin_layout Standard Some reusable routines may be compiled into a library, see the documentation for the assembler and linkage editor (which are in /share/sdcc/doc) for how to create a \emph on .lib \begin_inset Index idx status collapsed \begin_layout Plain Layout .lib \end_layout \end_inset \emph default library file. Libraries created in this manner can be included in the command line. Make sure you include the -L option to tell the linker where to look for these files if they are not in the current directory. Here is an example, assuming you have the source file \emph on foomain.c \emph default and a library \emph on foolib.lib \emph default in the directory \emph on mylib \emph default (if that is not the same as your current project): \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family sans \series bold sdcc foomain.c foolib.lib -L mylib \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family default \series default Note here that \emph on mylib \emph default must be an absolute path name. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset The most efficient way to use libraries is to keep separate modules in separate source files. The lib file now should name all the modules.rel \begin_inset Index idx status collapsed \begin_layout Plain Layout .rel \end_layout \end_inset files. For an example see the standard library file \emph on libsdcc.lib \emph default in the directory /share/lib/small. \end_layout \begin_layout Subsection Using sdar to Create and Manage Libraries \begin_inset Index idx status collapsed \begin_layout Plain Layout sdar \end_layout \end_inset \begin_inset CommandInset label LatexCommand label name "subsec:Using-sdar-to" \end_inset \end_layout \begin_layout Standard Support for sdar format libraries was introduced in SDCC 2.9.0. \series bold \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \series default Both the GNU and BSD ar format variants are supported by sdld linkers. \series bold \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \series default To create a library containing sdas object files, you should use the following sequence: \series bold \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard \family sans \series bold sdar -rc .lib \end_layout \begin_layout Section Command Line Options \begin_inset Index idx status collapsed \begin_layout Plain Layout Command Line Options \end_layout \end_inset \begin_inset CommandInset label LatexCommand label name "sec:Command-Line-Options" \end_inset \end_layout \begin_layout Subsection Processor Selection Options \begin_inset Index idx status collapsed \begin_layout Plain Layout Options processor selection \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Processor selection options \end_layout \end_inset \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mmcs51 \begin_inset Index idx status collapsed \begin_layout Plain Layout -mmcs51 \end_layout \end_inset \series default Generate code for the Intel MCS51 \begin_inset Index idx status collapsed \begin_layout Plain Layout MCS51 \end_layout \end_inset family of processors. This is the default processor target. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mds390 \begin_inset Index idx status collapsed \begin_layout Plain Layout -mds390 \end_layout \end_inset \series default Generate code for the Dallas DS80C390 \begin_inset Index idx status collapsed \begin_layout Plain Layout DS80C390 \end_layout \end_inset processor. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mds400 \begin_inset Index idx status collapsed \begin_layout Plain Layout -mds400 \end_layout \end_inset \series default Generate code for the Dallas DS80C400 \begin_inset Index idx status collapsed \begin_layout Plain Layout DS80C400 \end_layout \end_inset processor. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mhc08 \begin_inset Index idx status collapsed \begin_layout Plain Layout -mhc08 \end_layout \end_inset \series default Generate code for the Freescale/Motorola HC08 (aka 68HC08) \begin_inset Index idx status collapsed \begin_layout Plain Layout HC08 \end_layout \end_inset family of processors. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -ms08 \begin_inset Index idx status collapsed \begin_layout Plain Layout -ms08 \end_layout \end_inset \series default Generate code for the Freescale/Motorola S08 (aka 68HCS08, HCS08, CS08) \begin_inset Index idx status collapsed \begin_layout Plain Layout S08 \end_layout \end_inset family of processors. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mz80 \begin_inset Index idx status collapsed \begin_layout Plain Layout -mz80 \end_layout \end_inset \series default Generate code for the Zilog Z80 \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80 \end_layout \end_inset family of processors. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mz180 \begin_inset Index idx status collapsed \begin_layout Plain Layout -mz180 \end_layout \end_inset \series default Generate code for the Zilog Z180 \begin_inset Index idx status collapsed \begin_layout Plain Layout Z180 \end_layout \end_inset family of processors. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mr2k \begin_inset Index idx status collapsed \begin_layout Plain Layout -mr2k \end_layout \end_inset \series default Generate code for the Rabbit 2000 / Rabbit 3000 family of processors. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mr3ka \begin_inset Index idx status collapsed \begin_layout Plain Layout -mr3ka \end_layout \end_inset \series default Generate code for the Rabbit 3000A family of processors. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mgbz80 \begin_inset Index idx status collapsed \begin_layout Plain Layout -mgbz80 \end_layout \end_inset \series default Generate code for the LR35902 GameBoy Z80 \begin_inset Index idx status collapsed \begin_layout Plain Layout gbz80 (GameBoy Z80) \end_layout \end_inset processor. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mtlcs90 \begin_inset Index idx status open \begin_layout Plain Layout -mtlcs90 \end_layout \end_inset \series default Generate code for the Toshiba TLCS-90 processor. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mez80_z80 \begin_inset Index idx status open \begin_layout Plain Layout -mez80_z80 \end_layout \end_inset \series default Generate code for the Zilog eZ80 processor in Z80 mode. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mstm8 \begin_inset Index idx status collapsed \begin_layout Plain Layout -mstm8 \end_layout \end_inset \series default Generate code for the STMicroelectronics STM8 family of processors. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mpdk14 \begin_inset Index idx status open \begin_layout Plain Layout -mpdk14 \end_layout \end_inset \series default Generate code for Padauk processors with 14 bit wide program memory. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mpdk15 \begin_inset Index idx status open \begin_layout Plain Layout -mpdk15 \end_layout \end_inset \series default Generate code for Padauk processors with 15 bit wide program memory. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mpic14 \begin_inset Index idx status collapsed \begin_layout Plain Layout -mpic14 \end_layout \end_inset \series default Generate code for the Microchip PIC 14 \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC14 \end_layout \end_inset -bit processors (p16f84 and variants. In development, not complete). \end_layout \begin_layout Standard \begin_inset Note Note status collapsed \begin_layout Plain Layout p16f627 p16f628 p16f84 p16f873 p16f877? \end_layout \end_inset \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -mpic16 \begin_inset Index idx status collapsed \begin_layout Plain Layout -mpic16 \end_layout \end_inset \series default Generate code for the Microchip PIC 16 \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16 \end_layout \end_inset -bit processors (p18f452 and variants. In development, not complete). \end_layout \begin_layout Standard SDCC inspects the program name it was called with so the processor family can also be selected by renaming the sdcc binary (to f.e. z80-sdcc) or by calling SDCC from a suitable link. Option -m has higher priority than setting from program name. \end_layout \begin_layout Subsection Preprocessor Options \begin_inset Index idx status collapsed \begin_layout Plain Layout Options preprocessor \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Preprocessor!Options \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout sdcpp (preprocessor) \end_layout \end_inset \end_layout \begin_layout Standard SDCC uses \shape italic sdcpp \shape default , an adapted version of the GNU Compiler Collection \begin_inset Index idx status collapsed \begin_layout Plain Layout gcc (GNU Compiler Collection) \end_layout \end_inset preprocessor \emph on cpp \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout cpp|see \begin_inset ERT status collapsed \begin_layout Plain Layout { \end_layout \end_inset sdcpp \begin_inset ERT status collapsed \begin_layout Plain Layout } \end_layout \end_inset \end_layout \end_inset ( \emph on gcc \emph default \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://gcc.gnu.org/ \end_layout \end_inset ). If you need more dedicated options than those listed below please refer to the GCC \begin_inset space ~ \end_inset CPP \begin_inset space ~ \end_inset Manual at \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.gnu.org/software/gcc/onlinedocs/ \end_layout \end_inset . \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -I \begin_inset Index idx status collapsed \begin_layout Plain Layout -I \end_layout \end_inset \series default The additional location where the preprocessor will look for <..h> or \begin_inset Quotes eld \end_inset ..h \begin_inset Quotes erd \end_inset files. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -D \begin_inset Index idx status collapsed \begin_layout Plain Layout -D \end_layout \end_inset \series default Command line definition of macros. Passed to the preprocessor. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -M \begin_inset Index idx status collapsed \begin_layout Plain Layout -M \end_layout \end_inset \series default Tell the preprocessor to output a rule suitable for make describing the dependencies of each object file. For each source file, the preprocessor outputs one make-rule whose target is the object file name for that source file and whose dependencies are all the files `#include'd in it. This rule may be a single line or may be continued with ` \backslash '-newline if it is long. The list of rules is printed on standard output instead of the preprocessed C program. `-M' implies `-E \begin_inset Index idx status collapsed \begin_layout Plain Layout -E \end_layout \end_inset '. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -C \begin_inset Index idx status collapsed \begin_layout Plain Layout -C \end_layout \end_inset \series default Tell the preprocessor not to discard comments. Used with the `-E' option. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -MM \begin_inset Index idx status collapsed \begin_layout Plain Layout -MM \end_layout \end_inset \series default \size large \size default Like `-M' but the output mentions only the user header files included with `#include \begin_inset Quotes eld \end_inset file"'. System header files included with `#include ' are omitted. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -Aquestion(answer) \begin_inset Index idx status collapsed \begin_layout Plain Layout -Aquestion(answer) \end_layout \end_inset \series default Assert the answer answer for question, in case it is tested with a preprocessor conditional such as `#if #question(answer)'. `-A-' disables the standard assertions that normally describe the target machine. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -Umacro \begin_inset Index idx status collapsed \begin_layout Plain Layout -Umacro \end_layout \end_inset \series default Undefine macro macro. `-U' options are evaluated after all `-D' options, but before any `-include' and `-imacros' options. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -dM \begin_inset Index idx status collapsed \begin_layout Plain Layout -dM \end_layout \end_inset \series default Tell the preprocessor to output only a list of the macro definitions that are in effect at the end of preprocessing. Used with the `-E' option. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -dD \begin_inset Index idx status collapsed \begin_layout Plain Layout -dD \end_layout \end_inset \series default Tell the preprocessor to pass all macro definitions into the output, in their proper sequence in the rest of the output. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -dN \begin_inset Index idx status collapsed \begin_layout Plain Layout -dN \end_layout \end_inset \series default \size large \size default Like `-dD' except that the macro arguments and contents are omitted. Only `#define name' is included in the output. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -pedantic-parse-number \begin_inset Index idx status collapsed \begin_layout Plain Layout pedantic \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout -pedantic-parse-number \end_layout \end_inset \size large \bar under \begin_inset CommandInset label LatexCommand label name "lyx:-pedantic-parse-number" \end_inset \series default \bar default \size default Pedantic parse numbers so that situations like 0xfe-LO_B(3) are parsed properly and the macro LO_B(3) gets expanded. See also #pragma pedantic_parse_number \begin_inset CommandInset ref LatexCommand vpageref reference "ite:pedantic_parse_number" \end_inset in section \begin_inset CommandInset ref LatexCommand ref reference "sec:Pragmas" \end_inset \emph on Note: this functionality is not in conformance with C99 standard! \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -Wp \begin_inset space ~ \end_inset preprocessorOption[,preprocessorOption] \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout -Wp preprocessorOption[,preprocessorOption] \end_layout \end_inset ... Pass the preprocessorOption to the preprocessor \family typewriter sdcpp \family default \begin_inset Index idx status collapsed \begin_layout Plain Layout sdcpp (preprocessor) \end_layout \end_inset . \end_layout \begin_layout Subsection Optimization Options \begin_inset Index idx status collapsed \begin_layout Plain Layout Options optimization \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Optimization options \end_layout \end_inset \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -nogcse \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -nogcse \end_layout \end_inset \series default Will not do global common subexpression elimination, this option may be used when the compiler creates undesirably large stack/data spaces to store compiler temporaries ( \emph on s \emph default pill \emph on loc \emph default ations, sloc \begin_inset Index idx status collapsed \begin_layout Plain Layout sloc (spill location) \end_layout \end_inset ). A warning message will be generated when this happens and the compiler will indicate the number of extra bytes it allocated. It is recommended that this option NOT be used, #pragma \begin_inset space ~ \end_inset nogcse \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma nogcse \end_layout \end_inset can be used to turn off global subexpression elimination \begin_inset Index idx status collapsed \begin_layout Plain Layout Subexpression elimination \end_layout \end_inset for a given function only. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -noinvariant \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -noinvariant \end_layout \end_inset \series default Will not do loop invariant optimizations, this may be turned off for reasons explained for the previous option. For more details of loop optimizations performed see Loop Invariants in section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Loop-Optimizations" \end_inset . It is recommended that this option NOT be used, #pragma \begin_inset space ~ \end_inset noinvariant \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma noinvariant \end_layout \end_inset can be used to turn off invariant optimizations for a given function only. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -noinduction \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -noinduction \end_layout \end_inset \series default Will not do loop induction optimizations, see section strength reduction for more details. It is recommended that this option is NOT used, #pragma \begin_inset space ~ \end_inset noinduction \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma noinduction \end_layout \end_inset can be used to turn off induction optimizations for a given function only. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -noloopreverse \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -noloopreverse \end_layout \end_inset \series default \size large \size default Will not do loop reversal \begin_inset Index idx status collapsed \begin_layout Plain Layout Loop reversing \end_layout \end_inset optimization. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset - \series bold nolabelopt \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -nolabelopt \end_layout \end_inset Will not optimize labels (makes the dumpfiles more readable). \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-xinit-opt \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-xinit-opt \end_layout \end_inset \series default Will not memcpy initialized data from code space into xdata space. This saves a few bytes in code space if you don't have initialized data \begin_inset Index idx status collapsed \begin_layout Plain Layout Variable initialization \end_layout \end_inset . \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -nooverlay \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -nooverlay \end_layout \end_inset \series default The compiler will not overlay parameters and local variables of any function, see section Parameters and local variables for more details. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-peep \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-peep \end_layout \end_inset \series default Disable peep-hole optimization with built-in rules. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -peep-file \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -peep-file \end_layout \end_inset \begin_inset space ~ \end_inset This option can be used to use additional rules to be used by the peep hole optimizer. See section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Peephole-Optimizer" \end_inset \begin_inset space ~ \end_inset Peep Hole optimizations for details on how to write these rules. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -peep-asm \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -peep-asm \end_layout \end_inset \series default Pass the inline assembler code through the peep hole optimizer. This can cause unexpected changes to inline assembler code, please go through the peephole optimizer \begin_inset Index idx status collapsed \begin_layout Plain Layout Peephole optimizer \end_layout \end_inset rules defined in the source file tree '/peeph.def' before using this option. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -peep-return \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -peep-return \end_layout \end_inset \series default Let the peep hole optimizer do return optimizations. This is the default without \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset - \series default debug \series bold \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug \end_layout \end_inset \series default . \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-peep-return \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-peep-return \end_layout \end_inset \series default Do not let the peep hole optimizer do return optimizations. This is the default with \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset - \series default debug \series bold \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug \end_layout \end_inset \series default . \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -opt-code-speed \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -opt-code-speed \end_layout \end_inset \series default The compiler will optimize code generation towards fast code, possibly at the expense of code size. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -opt-code-size \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -opt-code-size \end_layout \end_inset \series default The compiler will optimize code generation towards compact code, possibly at the expense of code speed. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset - \series bold fomit-frame-pointer \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -fomit-frame-pointer \end_layout \end_inset Frame pointer will be omitted when the function uses no local variables. On the z80-related ports this option will result in the frame pointer always being omitted. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset - \series bold max-allocs-per-node \series default \begin_inset Index idx status open \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -max-allocs-per-node \end_layout \end_inset Setting this to a high value will result in increased compilation time and more optimized code being generated. Setting it to lower values speed up compilation, but does not optimize as much. The default value is 3000. This option currently only affects the hc08, s08, z80, z180, r2k, r3ka and gbz80 ports. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset - \series bold nolospre \series default \begin_inset Index idx status open \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -nolospre \end_layout \end_inset Disable lospre. lospre is an advanced redundancy elimination technique, essentially an improved variant of global subexpression elimination. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset - \series bold allow-unsafe-read \series default \begin_inset Index idx status open \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -allow-unsafe-read \end_layout \end_inset Allow optimizations to generate unsafe reads. This will enable additional optimizations, but can result in spurious reads from undefined memory addresses, which can be harmful if the target system uses certain ways of doing memory-mapped I/O. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset - \series bold nostdlibcall \series default \begin_inset Index idx status open \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -nostdlibcall \end_layout \end_inset Disable the optimization of calls to the standard library. \end_layout \begin_layout Subsection Other Options \begin_inset Index idx status collapsed \begin_layout Plain Layout Options other \end_layout \end_inset \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -v \begin_inset space ~ \end_inset - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -version \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -version \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout -v \end_layout \end_inset \series default displays the sdcc version. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -c \begin_inset space ~ \end_inset - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -compile-only \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -compile-only \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout -c \end_layout \end_inset \series default will compile and assemble the source, but will not call the linkage editor. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \series default \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \series bold -c1mode \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -c1mode \end_layout \end_inset \series default reads the preprocessed source from standard input and compiles it. The file name for the assembler output must be specified using the -o option. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -E \begin_inset Index idx status collapsed \begin_layout Plain Layout -E \end_layout \end_inset \series default Run only the C preprocessor \begin_inset Index idx status collapsed \begin_layout Plain Layout Preprocessor \end_layout \end_inset . Preprocess all the C source files specified and output the results to standard output. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -o \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout -o \end_layout \end_inset \series default The output path where everything will be placed or the file name used for all generated output files. If the parameter is a path, it must have a trailing slash (or backslash for the Windows binaries) to be recognized as a path. Note for Windows users: if the path contains spaces, it should be surrounded by quotes. The trailing backslash should be doubled in order to prevent escaping the final quote, for example: \emph on -o \begin_inset Quotes sld \end_inset F: \backslash Projects \backslash test3 \backslash output 1 \backslash \backslash \begin_inset Quotes srd \end_inset \emph default or put after the final quote, for example: \emph on -o \begin_inset Quotes sld \end_inset F: \backslash Projects \backslash test3 \backslash output 1 \begin_inset Quotes srd \end_inset \backslash \emph default . The path using slashes for directory delimiters can be used too, for example: \emph on -o \begin_inset Quotes sld \end_inset F:/Projects/test3/output 1/ \begin_inset Quotes srd \end_inset \emph default . \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \end_layout \end_inset \series default \size large \size default All functions in the source file will be compiled as \emph on reentrant \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout reentrant \end_layout \end_inset , i.e. the parameters and local variables will be allocated on the stack \begin_inset Index idx status collapsed \begin_layout Plain Layout stack \end_layout \end_inset . See section \begin_inset CommandInset ref LatexCommand ref reference "sec:Parameters-and-Local-Variables" \end_inset Parameters and Local Variables for more details. If this option is used all source files in the project should be compiled with this option. It automatically implies - \series bold \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \series default -int-long-reent and - \series bold \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \series default -float-reent. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -callee-saves \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -callee-saves \end_layout \end_inset \begin_inset CommandInset label LatexCommand label name "lyx:--callee-saves-function1[,function2][,function3]..." \end_inset function1[,function2][,function3].... \series default The compiler by default uses a caller saves convention for register saving across function calls, however this can cause unnecessary register pushing and popping when calling small functions from larger functions. This option can be used to switch the register saving convention for the function names specified. The compiler will not save registers when calling these functions, no extra code will be generated at the entry and exit (function prologue \series bold \begin_inset Index idx status collapsed \begin_layout Plain Layout function prologue \end_layout \end_inset \series default and epilogue \series bold \begin_inset Index idx status collapsed \begin_layout Plain Layout function epilogue \end_layout \end_inset \series default ) for these functions to save and restore the registers used by these functions, this can SUBSTANTIALLY reduce code and improve run time performance of the generated code. In the future the compiler (with inter procedural analysis) will be able to determine the appropriate scheme to use for each function call. DO NOT use this option for built-in functions such as _mulint..., if this option is used for a library function the appropriate library function needs to be recompiled with the same option. If the project consists of multiple source files then all the source file should be compiled with the same - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -callee-saves option string. Also see #pragma \begin_inset space ~ \end_inset callee_saves \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma callee \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset saves \end_layout \end_inset \begin_inset CommandInset ref LatexCommand vpageref reference "ite:callee_saves-function1[,function2[,function3...]]--" \end_inset . \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -all-callee-saves \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -all-callee-saves \end_layout \end_inset \series default Function of - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -callee-saves will be applied to all functions by default. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug \end_layout \end_inset \series default When this option is used the compiler will generate debug information. The debug information collected in a file with .cdb extension can be used with the SDCDB. For more information see documentation for SDCDB. Another file with a .omf extension contains debug information in AOMF or AOMF51 \begin_inset Index idx status collapsed \begin_layout Plain Layout AOMF, AOMF51 \end_layout \end_inset format which is commonly used by third party tools. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -S \begin_inset Index idx status collapsed \begin_layout Plain Layout -S \end_layout \end_inset \series default \size large \size default Stop after the stage of compilation proper; do not assemble. The output is an assembler code file for the input file specified. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -int-long-reent \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -int-long-reent \end_layout \end_inset \series default Integer (16 bit) and long (32 bit) libraries have been compiled as reentrant. Note by default these libraries are compiled as non-reentrant. See section Installation for more details. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -cyclomatic \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -cyclomatic \end_layout \end_inset \series default This option will cause the compiler to generate an information message for each function in the source file. The message contains some \emph on important \emph default information about the function. The number of edges and nodes the compiler detected in the control flow graph of the function, and most importantly the \emph on cyclomatic complexity \begin_inset Index idx status collapsed \begin_layout Plain Layout Cyclomatic complexity \end_layout \end_inset \emph default see section on Cyclomatic Complexity for more details. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -float-reent \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -float-reent \end_layout \end_inset \series default Floating point library is compiled as reentrant \begin_inset Index idx status collapsed \begin_layout Plain Layout reentrant \end_layout \end_inset . See section Installation for more details. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -fsigned-char \begin_inset Index idx status open \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -fsigned-char \end_layout \end_inset \series default By default char is \family typewriter unsigned \family default . To set the signess for characters to signed, use the option - \series bold \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \series default -fsigned-char. If this option is set and no signedness keyword (unsigned/signed) is given, a char will be unsigned. All other types are unaffected. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -nostdinc \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -nostdinc \end_layout \end_inset \series default This will prevent the compiler from passing on the default include path to the preprocessor. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -nostdlib \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -nostdlib \end_layout \end_inset \series default This will prevent the compiler from passing on the default library \begin_inset Index idx status collapsed \begin_layout Plain Layout Libraries \end_layout \end_inset path to the linker. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -verbose \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -verbose \end_layout \end_inset \series default Shows the various actions the compiler is performing. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -V \begin_inset Index idx status collapsed \begin_layout Plain Layout -V \end_layout \end_inset \series default Shows the actual commands the compiler is executing. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-c-code-in-asm \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-c-code-in-asm \end_layout \end_inset \series default Hides your ugly and inefficient c-code from the asm file, so you can always blame the compiler :) \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-peep-comments \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-peep-comments \end_layout \end_inset \series default Don't include peep-hole comments in the generated asm files even if - \series bold \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \series default -fverbose-asm option is specified. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -i-code-in-asm \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -i-code-in-asm \end_layout \end_inset \series default Include i-codes in the asm file. Sounds like noise but is helpful for debugging the compiler itself. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -less-pedantic \begin_inset Index idx status collapsed \begin_layout Plain Layout pedantic \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -less-pedantic \end_layout \end_inset \series default \begin_inset CommandInset label LatexCommand label name "lyx:--less-pedantic" \end_inset Disable some of the more pedantic warnings \begin_inset Index idx status collapsed \begin_layout Plain Layout Warnings \end_layout \end_inset . For more details, see the less_pedantic pragma \begin_inset CommandInset ref LatexCommand vpageref reference "ite:less_pedantic" \end_inset . \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-warning \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -disable-warning \end_layout \end_inset \series default Disable specific warning with number . \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -Werror \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -Werror \end_layout \end_inset \series default Treat all warnings as errors. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -print-search-dirs \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -print-search-dirs \end_layout \end_inset \series default Display the directories in the compiler's search path \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -vc \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -vc \end_layout \end_inset \series default Display errors and warnings using MSVC style, so you can use SDCC with the visual studio IDE \begin_inset Index idx status collapsed \begin_layout Plain Layout IDE \end_layout \end_inset . With SDCC both offering a GCC-like (the default) and a MSVC-like \begin_inset Index idx status collapsed \begin_layout Plain Layout MSVC output style \end_layout \end_inset output style, integration into most programming editors should be straightforwa rd. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-stdout \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-stdout \end_layout \end_inset \series default Send errors and warnings to stdout instead of stderr. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -Wa \begin_inset space ~ \end_inset asmOption[,asmOption] \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout -Wa asmOption[,asmOption] \end_layout \end_inset ... Pass the asmOption to the assembler \begin_inset Index idx status collapsed \begin_layout Plain Layout Options assembler \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Assembler options \end_layout \end_inset . See file sdcc/sdas/doc/asmlnk.txt for assembler options.cd \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-sdcc89 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-sdcc89 \end_layout \end_inset \series default Generally follow the ANSI C89 / ISO C90 standard, but allow some SDCC behaviour that conflicts with the standard. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c89 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c89 \end_layout \end_inset \series default Follow the ANSI C89 / ISO C90 standard. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-sdcc99 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-sdcc99 \end_layout \end_inset \series default Generally follow the ISO C99 standard, but allow some SDCC behaviour that conflicts with the standard. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c99 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-sdcc99 \end_layout \end_inset \series default Follow the ISO C99 standard. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-sdcc11 \begin_inset Index idx status open \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-sdcc11 \end_layout \end_inset \series default Generally follow the ISO C11 standard, but allow some SDCC behaviour that conflicts with the standard (default). \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-c11 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -std-sdcc11 \end_layout \end_inset \series default Follow the ISO C11 standard. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -codeseg \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -codeseg \end_layout \end_inset \begin_inset CommandInset label LatexCommand label name "lyx:-codeseg" \end_inset \begin_inset space ~ \end_inset The name to be used for the code \begin_inset Index idx status collapsed \begin_layout Plain Layout code \end_layout \end_inset segment, default CSEG. This is useful if you need to tell the compiler to put the code in a special segment so you can later on tell the linker to put this segment in a special place in memory. Can be used for instance when using bank switching to put the code in a bank. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -constseg \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -constseg \end_layout \end_inset \begin_inset space ~ \end_inset The name to be used for the const \begin_inset Index idx status collapsed \begin_layout Plain Layout const \end_layout \end_inset segment, default CONST. This is useful if you need to tell the compiler to put the const data in a special segment so you can later on tell the linker to put this segment in a special place in memory. Can be used for instance when using bank switching to put the const data in a bank. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -fdollars-in-identifiers \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -fdollars-in-identifiers \end_layout \end_inset \series default Permit '$' as an identifier character. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -more-pedantic \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -more-pedantic \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout pedantic \end_layout \end_inset Actually this is \series bold \emph on not \series default \emph default a SDCC compiler option but if you want \emph on more \emph default warnings you can use a separate tool dedicated to syntax checking like splint \begin_inset CommandInset label LatexCommand label name "lyx:more-pedantic-SPLINT" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout lint (syntax checking tool) \end_layout \end_inset \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.splint.org \end_layout \end_inset . To make your source files parseable by splint you will have to include \family sans lint.h \family default \begin_inset Index idx status collapsed \begin_layout Plain Layout splint (syntax checking tool) \end_layout \end_inset in your source file and add brackets around extended keywords (like \family sans \begin_inset Quotes sld \end_inset __at \begin_inset space ~ \end_inset \series bold ( \series default 0xab \series bold ) \series default \begin_inset Quotes srd \end_inset \family default and \family sans \begin_inset Quotes sld \end_inset __interrupt \begin_inset space ~ \end_inset (2) \begin_inset Quotes srd \end_inset \family default ). \begin_inset Newline newline \end_inset Splint has an excellent on line manual at \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.splint.org/manual/ \end_layout \end_inset and it's capabilities go beyond pure syntax checking. You'll need to tell splint the location of SDCC's include files so a typical command line could look like this: \begin_inset Newline newline \end_inset \family sans splint \begin_inset space ~ \end_inset -I \begin_inset space ~ \end_inset /usr/local/share/sdcc/include/mcs51/ \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset myprogram.c \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-non-free \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-non-free \end_layout \end_inset \begin_inset CommandInset label LatexCommand label name "lyx:--use-non-free" \end_inset Search / include non-free licensed libraries and header files, located under the non-free directory - see section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Search-Paths" \end_inset \end_layout \begin_layout Subsection Linker Options \begin_inset Index idx status collapsed \begin_layout Plain Layout Options linker \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Linker options \end_layout \end_inset \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \series default \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \series bold -lib-path \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -lib-path \end_layout \end_inset \series default \begin_inset space ~ \end_inset This option is passed to the linkage editor's additional libraries \begin_inset Index idx status collapsed \begin_layout Plain Layout Libraries \end_layout \end_inset search path. The path name must be absolute. Additional library files may be specified in the command line. See section Compiling programs for more details. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -L \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout -L \end_layout \end_inset \series default \begin_inset space ~ \end_inset Same as above. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xram-loc \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xram-loc \end_layout \end_inset \begin_inset space ~ \end_inset The start location of the external ram \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset xdata (mcs51, ds390 named address space) \end_layout \end_inset , default value is 0. The value entered can be in Hexadecimal or Decimal format, e.g.: - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xram-loc 0x8000 or - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xram-loc 32768. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -code-loc \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -code-loc \end_layout \end_inset \begin_inset space ~ \end_inset The start location of the code \begin_inset Index idx status open \begin_layout Plain Layout code \end_layout \end_inset segment, default value 0. Note when this option is used the interrupt vector table \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt vector table \end_layout \end_inset is also relocated to the given address. The value entered can be in Hexadecimal or Decimal format, e.g.: - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -code-loc 0x8000 or - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -code-loc 32768. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-loc \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-loc \end_layout \end_inset \begin_inset space ~ \end_inset By default the stack \begin_inset Index idx status collapsed \begin_layout Plain Layout stack \end_layout \end_inset is placed after the data segment for mcs51. By using this option the stack can be placed anywhere in the internal memory space of the mcs51. The value entered can be in Hexadecimal or Decimal format, e.g. - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-loc 0x20 or - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-loc 32. Since the sp register is incremented before a push or call, the initial sp will be set to one byte prior the provided value. The provided value should not overlap any other memory areas such as used register banks or the data segment and with enough space for the current application. The \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -pack-iram \series default \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -pack-iram \end_layout \end_inset option (which is now a default setting) will override this setting, so you should also specify the \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-pack-iram \series default \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-pack-iram \end_layout \end_inset option if you need to manually place the stack. \end_layout \begin_deeper \begin_layout Standard For stm8, by default the stack is placed at the device-specific reset value. By using this option, the stack can be placed anywhere in the lower 16-bits of the stm8 memory space. This is particularly useful for working around the stack roll-over antifeature present in some stm8 devices. \end_layout \end_deeper \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xstack-loc \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xstack-loc \end_layout \end_inset \begin_inset space ~ \end_inset By default the external stack \begin_inset Index idx status collapsed \begin_layout Plain Layout xstack \end_layout \end_inset is placed after the __pdata \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset pdata (mcs51, ds390 named address space) \end_layout \end_inset segment. Using this option the xstack can be placed anywhere in the external memory space of the 8051. The value entered can be in Hexadecimal or Decimal format, e.g. - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xstack-loc 0x8000 or - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-loc 32768. The provided value should not overlap any other memory areas such as the pdata or xdata segment and with enough space for the current application. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -data-loc \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -data-loc \end_layout \end_inset \begin_inset space ~ \end_inset The start location of the internal ram data \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset data (mcs51, ds390 named address space) \end_layout \end_inset segment. The value entered can be in Hexadecimal or Decimal format, eg. - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -data-loc 0x20 or - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -data-loc 32. (By default, the start location of the internal ram data segment is set as low as possible in memory, taking into account the used register banks and the bit segment at address 0x20. For example if register banks 0 and 1 are used without bit variables, the data segment will be set, if - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -data-loc is not used, to location 0x10.) \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -idata-loc \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -idata-loc \end_layout \end_inset \begin_inset space ~ \end_inset The start location of the indirectly addressable internal ram \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset idata (mcs51, ds390 named address space) \end_layout \end_inset of the 8051, default value is 0x80. The value entered can be in Hexadecimal or Decimal format, eg. - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -idata-loc 0x88 or - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -idata-loc 136. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -bit-loc \series default \begin_inset space ~ \end_inset The start location of the bit \begin_inset Index idx status collapsed \begin_layout Plain Layout bit \end_layout \end_inset addressable internal ram of the 8051. This is \emph on not \emph default implemented yet. Instead an option can be passed directly to the linker: -Wl \begin_inset space ~ \end_inset -bBSEG=. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -out-fmt-ihx \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -out-fmt-ihx \end_layout \end_inset \series default The linker output (final object code) is in Intel Hex format. \begin_inset Index idx status collapsed \begin_layout Plain Layout Intel hex format \end_layout \end_inset This is the default option. The format itself is documented in the documentation of srecord \begin_inset Index idx status collapsed \begin_layout Plain Layout srecord (bin, hex, ... tool) \end_layout \end_inset . \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -out-fmt-s19 \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -out-fmt-s19 \end_layout \end_inset \series default The linker output (final object code) is in Motorola S19 format \begin_inset Index idx status collapsed \begin_layout Plain Layout Motorola S19 format \end_layout \end_inset . The format itself is documented in the documentation of srecord. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -out-fmt-elf \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -out-fmt-s19 \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout HC08!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -out-fmt-elf \end_layout \end_inset \series default The linker output (final object code) is in ELF format \begin_inset Index idx status collapsed \begin_layout Plain Layout ELF format \end_layout \end_inset . (Currently only supported for the HC08 \begin_inset Index idx status collapsed \begin_layout Plain Layout HC08 \end_layout \end_inset and S08 processors) \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -Wl \begin_inset space ~ \end_inset linkOption[,linkOption] \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout -Wl linkOption[,linkOption] \end_layout \end_inset \begin_inset CommandInset label LatexCommand label name "lyx:-Wl option" \end_inset ... Pass the linkOption to the linker. If a bootloader is used an option like \begin_inset Quotes sld \end_inset -Wl \begin_inset space ~ \end_inset -bCSEG=0x1000 \begin_inset Quotes srd \end_inset would be typical to set the start of the code segment. Either use the double quotes around this option or use no space (e.g. -Wl-bCSEG=0x1000). See also #pragma constseg and #pragma codeseg in section \begin_inset CommandInset ref LatexCommand ref reference "sec:Pragmas" \end_inset . File sdcc/sdas/doc/asmlnk.txt has more on linker options. \end_layout \begin_layout Subsection MCS51 Options \begin_inset Index idx status collapsed \begin_layout Plain Layout Options MCS51 \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout MCS51 options \end_layout \end_inset \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-small \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-small \end_layout \end_inset \series default \size large \size default Generate code for Small model programs, see section Memory Models for more details. This is the default model. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-medium \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-medium \end_layout \end_inset \series default Generate code for Medium model programs, see section Memory Models for more details. If this option is used all source files in the project have to be compiled with this option. It must also be used when invoking the linker. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-large \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-large \end_layout \end_inset \series default Generate code for Large model programs, see section Memory Models for more details. If this option is used all source files in the project have to be compiled with this option. It must also be used when invoking the linker. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-huge \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-huge \end_layout \end_inset \series default Generate code for Huge model programs, see section Memory Models for more details. If this option is used all source files in the project have to be compiled with this option. It must also be used when invoking the linker. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xstack \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xstack \end_layout \end_inset \series default Uses a pseudo stack in the __pdata \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset pdata (mcs51, ds390 named address space) \end_layout \end_inset area (usually the first 256 bytes in the external ram) for allocating variables and passing parameters. See section \begin_inset CommandInset ref LatexCommand ref reference "subsec:External-Stack" \end_inset \begin_inset space ~ \end_inset External Stack for more details. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -iram-size \series default \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -iram-size \end_layout \end_inset Causes the linker to check if the internal ram usage is within limits of the given value. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xram-size \series default \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xram-size \end_layout \end_inset Causes the linker to check if the external ram usage is within limits of the given value. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -code-size \series default \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -code-size \end_layout \end_inset Causes the linker to check if the code memory usage is within limits of the given value. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-size \series default \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-size \end_layout \end_inset Causes the linker to check if there is at minimum bytes for stack. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -pack-iram \series default \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -pack-iram \end_layout \end_inset Causes the linker to use unused register banks for data variables and pack data, idata and stack together. This is the default and this option will probably be removed along with the removal of - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-pack-iram. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-pack-iram \series default \begin_inset space ~ \end_inset (deprecated) \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-pack-iram \end_layout \end_inset Causes the linker to use old style for allocating memory areas. This option is now deprecated and will be removed in future versions. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -acall-ajmp \series default \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -acall-ajmp \end_layout \end_inset Replaces the three byte instructions lcall/ljmp with the two byte instructions acall/ajmp. Only use this option if your code is in the same 2k block of memory. You may need to use this option for some 8051 derivatives which lack the lcall/ljmp instructions. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-ret-without-call \series default \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-ret-without-call \end_layout \end_inset Causes the code generator to insert an extra lcall or acall instruction whenever it needs to use a ret instruction in a context other than a function returning. This option is needed when using the Infineon \begin_inset Index idx status collapsed \begin_layout Plain Layout Infineon \end_layout \end_inset XC800 series microcontrollers to keep its Memory Extension Stack balanced. \end_layout \begin_layout Subsection DS390 / DS400 Options \begin_inset Index idx status collapsed \begin_layout Plain Layout Options DS390 \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout DS390 \end_layout \end_inset \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-flat24 \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout DS390!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-flat24 \end_layout \end_inset \size large \size default Generate 24-bit flat mode code. This is the one and only that the ds390 code generator supports right now and is default when using \emph on -mds390 \emph default . See section Memory Models for more details. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -protect-sp-update \begin_inset Index idx status collapsed \begin_layout Plain Layout DS390!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -protect-sp-update \end_layout \end_inset \series default disable interrupts during ESP:SP updates. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-10bit \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout DS390!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-10bit \end_layout \end_inset Generate code for the 10 bit stack mode of the Dallas DS80C390 part. This is the one and only that the ds390 code generator supports right now and is default when using \emph on -mds390 \emph default . In this mode, the stack is located in the lower 1K of the internal RAM, which is mapped to 0x400000. Note that the support is incomplete, since it still uses a single byte as the stack pointer. This means that only the lower 256 bytes of the potential 1K stack space will actually be used. However, this does allow you to reclaim the precious 256 bytes of low RAM for use for the DATA and IDATA segments. The compiler will not generate any code to put the processor into 10 bit stack mode. It is important to ensure that the processor is in this mode before calling any re-entrant functions compiled with this option. In principle, this should work with the \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \end_layout \end_inset \emph default option, but that has not been tested. It is incompatible with the \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xstack \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xstack \end_layout \end_inset \emph default option. It also only makes sense if the processor is in 24 bit contiguous addressing mode (see the \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-flat24 option \emph default ). \series bold \begin_inset Note Note status collapsed \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-8-bit - switches off the 10-bit mode \end_layout \end_inset \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-probe \begin_inset Index idx status collapsed \begin_layout Plain Layout DS390!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-probe \end_layout \end_inset \series default insert call to function __stack_probe at each function prologue. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -tini-libid \begin_inset Index idx status collapsed \begin_layout Plain Layout DS390!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -tini-libid \end_layout \end_inset \series default LibraryID used in -mTININative. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-accelerator \begin_inset Index idx status collapsed \begin_layout Plain Layout DS390!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-accelerator \end_layout \end_inset \series default generate code for DS390 Arithmetic Accelerator. \end_layout \begin_layout Subsection Options common to all z80-related ports (z80, z180, r2k, r3ka, gbz80, tlcs90, ez80_z80) \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-std-crt0 \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-std-crt0 \end_layout \end_inset When linking, skip the standard crt0.rel object file. You must provide your own crt0.rel for your system when linking. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -callee-saves-bc \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -callee-saves-bc \end_layout \end_inset \size large \size default Force a called function to always save BC. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -codeseg \series default \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -codeseg \end_layout \end_inset Use for the code segment name. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -constseg \series default \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -constseg \end_layout \end_inset Use for the const segment name. \end_layout \begin_layout Subsection Z80 Options \begin_inset Index idx status collapsed \begin_layout Plain Layout Options Z80 \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80 \end_layout \end_inset (apply to z80, z180, r2k, r3ka, tlcs90, ez80_z80) \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -portmode= \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -portmode= \end_layout \end_inset Determinate PORT I/O mode ( is z80 or z180). \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -asm= \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -asm= \end_layout \end_inset Define assembler name ( is rgbds, sdasz80, isas or z80asm). \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -reserve-regs-iy \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -reserve-regs-iy \end_layout \end_inset \size large \size default This option tells the compiler that it is not allowed to use register pair iy. The option can be useful for systems where iy is reserved for the OS. This option is incompatible with - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -fomit-frame-pointer. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -oldralloc \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -oldralloc \end_layout \end_inset \size large \size default Use old register allocator. The old register allocator is typically is faster than the current one, but the current one generates better code. This differences are the most noticeable, when a high value for - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -max-allocs-per-node is used. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -fno-omit-frame-pointer \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -fno-omit-frame-pointer \end_layout \end_inset \size large \size default Never omit the frame pointer. \end_layout \begin_layout Subsection GBZ80 Options \begin_inset Index idx status collapsed \begin_layout Plain Layout Options GBZ80 \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout GBZ80 \end_layout \end_inset \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -bo \series default \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout GBZ80!Options!-bo \end_layout \end_inset Use code bank . \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold -ba \series default \begin_inset space ~ \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout GBZ80!Options!-ba \end_layout \end_inset Use data bank . \end_layout \begin_layout Subsection Intermediate Dump Options \begin_inset CommandInset label LatexCommand label name "subsec:Intermediate-Dump-Options" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Options intermediate dump \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Intermediate dump options \end_layout \end_inset \end_layout \begin_layout Standard The following options are provided for the purpose of retargetting and debugging the compiler. They provide a means to dump the intermediate code (iCode \begin_inset Index idx status collapsed \begin_layout Plain Layout iCode \end_layout \end_inset ) generated by the compiler in human readable form at various stages of the compilation process. More on iCodes see chapter \begin_inset CommandInset ref LatexCommand ref reference "subsec:The-anatomy-of" \end_inset \begin_inset Quotes srd \end_inset The anatomy of the compiler \begin_inset Quotes srd \end_inset . \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -dum-ast \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -dump-ast \end_layout \end_inset \series default This option will cause the compiler to dump the abstract syntax tree to the econsole. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -dump-i-code \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -dump-i-code \end_layout \end_inset \size large \series default \size default Will dump iCodes at various stages into files named \emph on .dump \emph default . \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -dump-graphs \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -dump-graphs \end_layout \end_inset \size large \series default \size default Will dump internal representations as graphviz .dot files. Depending on other options, this can include the control-flow graph at lospre, insertion of bank selection instructions or register allocation and the conflict graph and tree-decomposition at register allocation. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -fverbose-asm \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-gen-comments \end_layout \end_inset \series default Include code generator and peep-hole comments in the generated asm files. \end_layout \begin_layout Subsection Redirecting output on Windows Shells \end_layout \begin_layout Standard By default SDCC writes its error messages to \begin_inset Quotes sld \end_inset standard error \begin_inset Quotes srd \end_inset . To force all messages to \begin_inset Quotes sld \end_inset standard output \begin_inset Quotes srd \end_inset use \series bold - \series default \emph on \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \series bold \emph default - \series default use-stdout \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-stdout \end_layout \end_inset . Additionally, if you happen to have visual studio installed in your windows machine, you can use it to compile your sources using a custom build and the SDCC - \emph on \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \emph default -vc \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -vc \end_layout \end_inset option. Something like this should work: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \series bold c: \backslash sdcc \backslash bin \backslash sdcc.exe - \series default \emph on \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \series bold \emph default -vc - \series default \emph on \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \series bold \emph default -model-large -c $(InputPath) \end_layout \begin_layout Section Environment variables \begin_inset Index idx status collapsed \begin_layout Plain Layout Environment variables \end_layout \end_inset \end_layout \begin_layout Standard SDCC recognizes the following environment variables: \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold SDCC_LEAVE_SIGNALS \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Environment variables!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset LEAVE \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset SIGNALS \end_layout \end_inset \series default SDCC installs a signal handler \begin_inset Index idx status collapsed \begin_layout Plain Layout signal handler \end_layout \end_inset to be able to delete temporary files after an user break (^C) or an exception. If this environment variable is set, SDCC won't install the signal handler in order to be able to debug SDCC. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold TMP, \begin_inset space ~ \end_inset TEMP, \begin_inset space ~ \end_inset TMPDIR \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Environment variables!TMP, TEMP, TMPDIR \end_layout \end_inset \series default Path, where temporary files will be created. The order of the variables is the search order. In a standard *nix environment these variables are not set, and there's no need to set them. On Windows it's recommended to set one of them. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold SDCC_HOME \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Environment variables!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset HOME \end_layout \end_inset \series default Path, see section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Install-paths" \end_inset \begin_inset space ~ \end_inset \begin_inset Quotes sld \end_inset Install Paths \begin_inset Quotes srd \end_inset . \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold SDCC_INCLUDE \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Environment variables!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset INCLUDE \end_layout \end_inset \series default Path, see section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Search-Paths" \end_inset \begin_inset space ~ \end_inset \begin_inset Quotes sld \end_inset Search Paths \begin_inset Quotes srd \end_inset . \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series bold SDCC_LIB \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Environment variables!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset LIB \end_layout \end_inset \series default Path, see section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Search-Paths" \end_inset \begin_inset space ~ \end_inset \begin_inset Quotes sld \end_inset Search Paths \begin_inset Quotes srd \end_inset .. \end_layout \begin_layout Standard There are some more environment variables recognized by SDCC, but these are mainly used for debugging purposes. They can change or disappear very quickly, and will never be documented \begin_inset Foot status collapsed \begin_layout Plain Layout if you are curious search in SDCC's sources for \family typewriter \begin_inset Quotes sld \end_inset getenv \begin_inset Quotes srd \end_inset \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Environment variables!undocumented \end_layout \end_inset . \end_layout \begin_layout Section SDCC Language Extensions \end_layout \begin_layout Standard SDCC supports some language extensions useful for embedded systems. These include named address spaces (see also section 5.1 of the Embedded C standard). SDCC supports both intrinsic named address spaces (which ones are supported depends on the target architecture) and non-intrinsic named address spaces (defined by the user using the keyword __addressmod, they are particularly useful with custom bank-switching hardware). Unlike the Embedded C standard, SDCC allows local variables to have an intrinsic named address space even when not explicitly declared as static or extern. \end_layout \begin_layout Subsection MCS51/DS390 intrinsic named address spaces \end_layout \begin_layout Standard SDCC supports the following MCS51-specific intrinsic address spaces: \end_layout \begin_layout Standard \begin_inset Graphics filename MCS51_named.svg \end_inset \end_layout \begin_layout Subsubsection __data \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset data (mcs51, ds390 named address space) \end_layout \end_inset / __near \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset near (named address space) \end_layout \end_inset \end_layout \begin_layout Standard This is the \series bold default \series default (generic) address space for the Small Memory model. Variables in this address space will be allocated in the directly addressable portion of the internal RAM of a 8051, e.g.: \end_layout \begin_layout Verse \family typewriter __data unsigned char test_data; \end_layout \begin_layout Standard Writing 0x01 to this variable generates the assembly code: \end_layout \begin_layout Verse \family typewriter 75*00 01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _test_data,#0x01 \end_layout \begin_layout Subsubsection __xdata \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset xdata (mcs51, ds390 named address space) \end_layout \end_inset / __far \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset far (named address space) \end_layout \end_inset \end_layout \begin_layout Standard Variables in this address space will be placed in the external RAM. This is the \series bold default \series default (generic) address space for the Large Memory model, e.g.: \end_layout \begin_layout Verse \family typewriter __xdata unsigned char test_xdata; \end_layout \begin_layout Standard Writing 0x01 to this variable generates the assembly code: \end_layout \begin_layout Verse \family typewriter 90s00r00 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dptr,#_test_xdata \begin_inset Newline newline \end_inset 74 \begin_inset space ~ \end_inset 01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,#0x01 \begin_inset Newline newline \end_inset F0 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset movx \begin_inset space ~ \end_inset @dptr,a \end_layout \begin_layout Subsubsection __idata \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset idata (mcs51, ds390 named address space) \end_layout \end_inset \end_layout \begin_layout Standard Variables in this address space will be allocated into the indirectly addressabl e portion of the internal ram of a 8051, e.g.: \end_layout \begin_layout Verse \family typewriter __idata unsigned char test_idata; \end_layout \begin_layout Standard Writing 0x01 to this variable generates the assembly code: \end_layout \begin_layout Verse \family typewriter 78r00 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset r0,#_test_idata \begin_inset Newline newline \end_inset 76 \begin_inset space ~ \end_inset 01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset @r0,#0x01 \end_layout \begin_layout Standard Please note, the first 128 byte of idata physically access the same RAM as the data memory. The original 8051 had 128 byte idata memory, nowadays most devices have 256 byte idata memory. The stack \begin_inset Index idx status collapsed \begin_layout Plain Layout stack \end_layout \end_inset is located in idata memory (unless \begin_inset Flex Code status open \begin_layout Plain Layout --xstack \end_layout \end_inset is specified). \end_layout \begin_layout Subsubsection __pdata \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset pdata (mcs51, ds390 named address space) \end_layout \end_inset \end_layout \begin_layout Standard Paged xdata access is just as straightforward as using the other addressing modes of a 8051. It is typically located at the start of xdata and has a maximum size of 256 bytes. The following example writes 0x01 to the pdata variable. Please note, pdata access physically accesses xdata memory. The high byte of the address is determined by port P2 \begin_inset Index idx status collapsed \begin_layout Plain Layout P2 (mcs51 sfr) \end_layout \end_inset (or in case of some 8051 variants by a separate Special Function Register, see section \begin_inset CommandInset ref LatexCommand ref reference "subsec:MCS51-variants" \end_inset ). This is the \series bold default \series default (generic) address space for the Medium Memory model, e.g.: \end_layout \begin_layout Verse \family typewriter __pdata unsigned char test_pdata; \end_layout \begin_layout Standard Writing 0x01 to this variable generates the assembly code: \end_layout \begin_layout Verse \family typewriter 78r00 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r0,#_test_pdata \begin_inset Newline newline \end_inset 74 01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,#0x01 \begin_inset Newline newline \end_inset F2 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset movx @r0,a \end_layout \begin_layout Standard If the - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xstack \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xstack \end_layout \end_inset option is used the pdata memory area is followed by the xstack memory area and the sum of their sizes is limited to 256 bytes. \end_layout \begin_layout Subsubsection __code \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset code \end_layout \end_inset \end_layout \begin_layout Standard 'Variables' in this address space will be placed in the code memory: \end_layout \begin_layout Verse \family typewriter __code unsigned char test_code; \end_layout \begin_layout Standard Read access to this variable generates the assembly code: \end_layout \begin_layout Verse \family typewriter 90s00r6F \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov dptr,#_test_code \begin_inset Newline newline \end_inset E4 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset clr a \begin_inset Newline newline \end_inset 93 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset movc a,@a+dptr \end_layout \begin_layout Standard \family typewriter char \family default indexed arrays of characters in code memory can be accessed efficiently: \end_layout \begin_layout Verse \family typewriter __code char test_array[] = {'c','h','e','a','p'}; \end_layout \begin_layout Standard Read access to this array using an 8-bit unsigned index generates the assembly code: \end_layout \begin_layout Verse \family typewriter E5*00 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,_index \end_layout \begin_layout Verse \family typewriter 90s00r41 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov dptr,#_test_array \end_layout \begin_layout Verse \family typewriter 93 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset movc a,@a+dptr \end_layout \begin_layout Subsubsection __bit \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset bit \end_layout \end_inset \end_layout \begin_layout Standard This is a data-type and an address space. When a variable is declared as a bit, it is allocated into the bit addressable memory of 8051, e.g.: \end_layout \begin_layout Verse \family typewriter __bit test_bit; \end_layout \begin_layout Standard Writing 1 to this variable generates the assembly code: \end_layout \begin_layout Verse \family typewriter D2*00 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset setb \begin_inset space ~ \end_inset _test_bit \end_layout \begin_layout Standard The bit addressable memory consists of 128 bits which are located from 0x20 to 0x2f in data memory. \begin_inset Newline newline \end_inset Apart from this 8051 specific intrinsic named address space most architectures support ANSI-C bit-fields \begin_inset Index idx status open \begin_layout Plain Layout bit-fields \end_layout \end_inset \begin_inset Foot status collapsed \begin_layout Plain Layout Not really meant as examples, but nevertheless showing what bit-fields are about: device/include/mc68hc908qy.h and support/regression/tests/bitfields.c \end_layout \end_inset . In accordance with ISO/IEC 9899 bits and bitfields without an explicit signed modifier are implemented as unsigned. \end_layout \begin_layout Subsubsection __sfr \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset sfr \end_layout \end_inset / __sfr16 \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset sfr16 \end_layout \end_inset / __sfr32 \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset sfr32 \end_layout \end_inset / __sbit \begin_inset Index idx status collapsed \begin_layout Plain Layout sbit \end_layout \end_inset \end_layout \begin_layout Standard Like the __bit keyword, \emph on __sfr / __sfr16 / __sfr32 / __sbit \emph default signify both a data-type and named address space, they are used to describe the \emph on s \emph default pecial \emph on f \emph default unction \emph on r \emph default egisters and special \emph on __bit \emph default variables of a 8051, eg: \end_layout \begin_layout Verse \family typewriter __sfr __at \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset at \end_layout \end_inset (0x80) P0; \begin_inset space ~ \end_inset /* special function register P0 at location 0x80 */ \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset /* 16 bit special function register combination for timer 0 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset with the high byte at location 0x8C and the low byte at location 0x8A */ \begin_inset Newline newline \end_inset __sfr16 __at (0x8C8A) TMR0; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset __sbit __at \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset at \end_layout \end_inset (0xd7) CY; \begin_inset space ~ \end_inset /* CY (Carry Flag \begin_inset Index idx status collapsed \begin_layout Plain Layout Flags \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Carry flag \end_layout \end_inset ) */ \end_layout \begin_layout Standard Special function registers which are located on an address dividable by 8 are bit-addressable, an \emph on __sbit \emph default addresses a specific bit within these sfr. \begin_inset Newline newline \end_inset 16 Bit and 32 bit special function register combinations which require a certain access order are better not declared using \emph on __sfr16 \emph default or \emph on __sfr32. \emph default Although SDCC usually accesses them Least Significant Byte (LSB) first, this is not guaranteed. \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard Please note, if you use a header file which was written for another compiler then the __sfr / __sfr16 / __sfr32 / __sbit intrinsic named address spaces will most likely be \emph on not \emph default compatible. Specifically the syntax \family typewriter \begin_inset space ~ \end_inset sfr P0 = 0x80; \begin_inset space ~ \end_inset \family default is compiled \emph on without warning \emph default by SDCC to an assignment of 0x80 to a variable called P0 \family typewriter . \family default \series bold Nevertheless with the file \family typewriter compiler.h \begin_inset Index idx status collapsed \begin_layout Plain Layout compiler.h (include file) \end_layout \end_inset \family default it is possible to write header files \begin_inset Index idx status collapsed \begin_layout Plain Layout Header files \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Include files \end_layout \end_inset which can be shared among different compilers (see section \begin_inset CommandInset ref LatexCommand ref reference "sec:Porting-code-to-other-compilers" \end_inset ). \end_layout \begin_layout Subsubsection Pointers \begin_inset Index idx status collapsed \begin_layout Plain Layout Pointer \end_layout \end_inset to MCS51/DS390 intrinsic named address spaces \end_layout \begin_layout Standard SDCC allows (via language extensions) pointers to explicitly point to any of the named address spaces \begin_inset Index idx status collapsed \begin_layout Plain Layout Memory model \end_layout \end_inset of the 8051. In addition to the explicit pointers, the compiler uses (by default) generic pointers which can be used to point to any of the memory spaces. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Pointer declaration examples: \end_layout \begin_layout Verse \family typewriter /* pointer physically in internal ram pointing to object in external ram */ \begin_inset Newline newline \end_inset __xdata unsigned char * __data p; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset /* pointer physically in external ram pointing to object in internal ram */ \begin_inset Newline newline \end_inset __data unsigned char * __xdata p; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset /* pointer physically in code rom pointing to data in xdata space */ \begin_inset Newline newline \end_inset __xdata unsigned char * __code p; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset /* pointer physically in code space pointing to data in code space */ \begin_inset Newline newline \end_inset __code unsigned char * __code p; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset /* generic pointer physically located in xdata space */ \begin_inset Newline newline \end_inset unsigned char * __xdata p; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset /* generic pointer physically located in default memory space */ \begin_inset Newline newline \end_inset unsigned char * p; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset /* the following is a function pointer \begin_inset Index idx status collapsed \begin_layout Plain Layout function pointer \end_layout \end_inset physically located in data space */ \begin_inset Newline newline \end_inset char (* __data fp)(void); \end_layout \begin_layout Standard Well you get the idea. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset All unqualified pointers are treated as 3-byte (4-byte for the ds390) \emph on generic \emph default pointers. \size small \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \size default The highest order byte of the \emph on generic \emph default pointers contains the data space information. Assembler support routines are called whenever data is stored or retrieved using \emph on generic \emph default pointers. These are useful for developing reusable library \begin_inset Index idx status collapsed \begin_layout Plain Layout Libraries \end_layout \end_inset routines. Explicitly specifying the pointer \begin_inset Index idx status collapsed \begin_layout Plain Layout Pointer \end_layout \end_inset type will generate the most efficient code. \end_layout \begin_layout Subsubsection Notes on MCS51 memory \begin_inset Index idx status collapsed \begin_layout Plain Layout MCS51 memory \end_layout \end_inset layout \end_layout \begin_layout Standard The 8051 family of microcontrollers have a minimum of 128 bytes of internal RAM memory which is structured as follows: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset - Bytes 00-1F - 32 bytes to hold up to 4 banks of the registers R0 to R7, \begin_inset Newline newline \end_inset - Bytes 20-2F - 16 bytes to hold 128 bit \begin_inset Index idx status collapsed \begin_layout Plain Layout bit \end_layout \end_inset variables and, \begin_inset Newline newline \end_inset - Bytes 30-7F - 80 bytes for general purpose use. \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard Additionally some members of the MCS51 family may have up to 128 bytes of additional, indirectly addressable, internal RAM memory ( \emph on __idata \emph default \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset idata (mcs51, ds390 named address space) \end_layout \end_inset ). Furthermore, some chips may have some built in external memory ( \emph on __xdata \emph default \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset xdata (mcs51, ds390 named address space) \end_layout \end_inset ) which should not be confused with the internal, directly addressable RAM memory ( \emph on __data \emph default \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset data (mcs51, ds390 named address space) \end_layout \end_inset ). Sometimes this built in \emph on __xdata \emph default memory has to be activated before using it (you can probably find this information on the datasheet of the microcontroller your are using, see also section \begin_inset CommandInset ref LatexCommand ref reference "subsec:MCS51-Startup-Code" \end_inset \begin_inset space ~ \end_inset Startup-Code). \end_layout \begin_layout Standard Normally SDCC will only use the first bank \begin_inset Index idx status open \begin_layout Plain Layout register bank (mcs51, ds390) \end_layout \end_inset of registers (register bank 0), but it is possible to specify that other banks of registers (keyword \emph on __using \emph default \emph on \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset using (mcs51, ds390 register bank) \end_layout \end_inset \emph default ) should be used for example in interrupt \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset interrupt \end_layout \end_inset routines. By default, the compiler will place the stack after the last byte of allocated memory for variables. For example, if the first 2 banks of registers are used, and only four bytes are used for \emph on data \emph default variables, it will position the base of the internal stack at address 20 (0x14). This implies that as the stack \begin_inset Index idx status collapsed \begin_layout Plain Layout stack \end_layout \end_inset grows, it will use up the remaining register banks, and the 16 bytes used by the 128 bit variables, and 80 bytes for general purpose use. If any bit variables are used, the data variables will be placed in unused register banks and after the byte holding the last bit variable. For example, if register banks 0 and 1 are used, and there are 9 bit variables (two bytes used), \emph on data \emph default variables will be placed starting from address 0x10 to 0x20 and continue at address 0x22. You can also use - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -data-loc \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -data-loc \end_layout \end_inset to specify the start address of the \emph on data \emph default and - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -iram-size \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -iram-size \end_layout \end_inset to specify the size of the total internal RAM ( \emph on data \emph default + \emph on idata \emph default ). \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard By default the 8051 linker will place the stack after the last byte of (i)data variables. Option - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-loc \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-loc \end_layout \end_inset allows you to specify the start of the stack, i.e. you could start it after any data in the general purpose area. If your microcontroller has additional indirectly addressable internal RAM ( \emph on idata \emph default ) you can place the stack on it. You may also need to use - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xdata-loc \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xdata-loc \end_layout \end_inset to set the start address of the external RAM ( \emph on xdata \emph default ) and - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xram-size \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xram-size \end_layout \end_inset to specify its size. Same goes for the code memory, using - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -code-loc \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -code-loc \end_layout \end_inset and - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -code-size \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -code-size \end_layout \end_inset . If in doubt, don't specify any options and see if the resulting memory layout is appropriate, then you can adjust it. \end_layout \begin_layout Standard The linker generates two files with memory allocation information. The first, with extension .map \begin_inset Index idx status collapsed \begin_layout Plain Layout .map \end_layout \end_inset shows all the variables and segments. The second with extension .mem \begin_inset Index idx status collapsed \begin_layout Plain Layout .mem \end_layout \end_inset shows the final memory layout. The linker will complain either if memory segments overlap, there is not enough memory, or there is not enough space for stack. If you get any linking warnings and/or errors related to stack or segments allocation, take a look at either the .map or .mem files to find out what the problem is. The .mem file may even suggest a solution to the problem. \end_layout \begin_layout Subsection Z80/Z180/eZ80 intrinsic named address spaces \end_layout \begin_layout Subsubsection __sfr \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset sfr \end_layout \end_inset (in/out to 8-bit addresses) \end_layout \begin_layout Standard The Z80 \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80 \end_layout \end_inset family has separate address spaces for memory and \emph on i \emph default nput/ \emph on o \emph default utput memory. I/O memory \begin_inset Index idx status collapsed \begin_layout Plain Layout I/O memory (Z80, Z180) \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80!I/O memory \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Z180!I/O memory \end_layout \end_inset is accessed with special instructions, e.g.: \end_layout \begin_layout Verse \family typewriter __sfr __at 0x78 IoPort; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* define a var in I/O space at 78h called IoPort */ \end_layout \begin_layout Standard Writing 0x01 to this variable generates the assembly code: \end_layout \begin_layout Verse \family typewriter 3E 01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ld a,#0x01 \begin_inset Newline newline \end_inset D3 78 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset out (_IoPort),a \end_layout \begin_layout Subsubsection __banked __sfr \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset sfr \end_layout \end_inset (in/out to 16-bit addresses) \end_layout \begin_layout Standard The keyword \emph on __banked \emph default is used to support 16 bit addresses in I/O memory e.g.: \end_layout \begin_layout Verse \family typewriter __sfr __banked __at \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset at \end_layout \end_inset 0x123 IoPort; \end_layout \begin_layout Standard Writing 0x01 to this variable generates the assembly code: \end_layout \begin_layout Verse \family typewriter 01 23 01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ld bc,#_IoPort \begin_inset Newline newline \end_inset 3E 01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ld a,#0x01 \begin_inset Newline newline \end_inset ED 79 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset out (c),a \end_layout \begin_layout Subsubsection __sfr \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset sfr \end_layout \end_inset (in0/out0 to 8 bit addresses on Z180 \begin_inset Index idx status collapsed \begin_layout Plain Layout Z180 \end_layout \end_inset /HD64180 \begin_inset Index idx status collapsed \begin_layout Plain Layout HD64180 (see Z180) \end_layout \end_inset ) \end_layout \begin_layout Standard The compiler option - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -portmode \begin_inset Index idx status collapsed \begin_layout Plain Layout Z180!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -portmode \end_layout \end_inset =180 (80) and a compiler #pragma \begin_inset space ~ \end_inset portmode \begin_inset Index idx status collapsed \begin_layout Plain Layout Z180!Pragmas! \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma portmode \end_layout \end_inset z180 (z80) is used to turn on (off) the Z180/HD64180 port addressing instructio ns \family typewriter in0/out0 \family default instead of \family typewriter in/out \family default . If you include the file z180.h this will be set automatically. \end_layout \begin_layout Subsection HC08/S08 intrinsic named address spaces \end_layout \begin_layout Subsubsection __data \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset data (hc08 named address space) \end_layout \end_inset \end_layout \begin_layout Standard Variables int the address space __data resides in the first 256 bytes of memory (the direct page). The HC08 \begin_inset Index idx status collapsed \begin_layout Plain Layout HC08 \end_layout \end_inset is most efficient at accessing variables (especially pointers) stored here. \end_layout \begin_layout Subsubsection __xdata \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset xdata (hc08 named address space) \end_layout \end_inset \end_layout \begin_layout Standard Variables in the address space__xdata can reside anywhere in memory. This is the default (generic address space). \end_layout \begin_layout Subsection PDK14/PDK15 intrinsic named address spaces \end_layout \begin_layout Subsubsection __sfr \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset sfr \end_layout \end_inset \end_layout \begin_layout Standard The Padauk family has separate address spaces for memory and \emph on i \emph default nput/ \emph on o \emph default utput memory. I/O memory is accessed with special instructions, e.g.: \end_layout \begin_layout Verse \family typewriter __sfr __at 0x18 gpcc; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* define a var in I/O space at 18h called gpcc */ \end_layout \begin_layout Subsubsection __sfr16 \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset sfr16 \end_layout \end_inset \end_layout \begin_layout Standard The Padauk family has a 16-bit timer accessed with special instructions. \end_layout \begin_layout Subsection Non-intrinsic named address spaces \begin_inset Index idx status open \begin_layout Plain Layout Non-intrinsic named address spaces \end_layout \end_inset \end_layout \begin_layout Standard SDCC supports user-defined non-intrinsic named address spaces. So far SDCC only supports them for bank-switching. You need to have a function that switches to the desired memory bank and declare a corresponding named address space: \end_layout \begin_layout Verse \family typewriter void setb0(void); // The function that sets the currently active memory bank to b0 \begin_inset Newline newline \end_inset void setb1(void); // The function that sets the currently active memory bank to b1 \begin_inset Newline newline \end_inset __addressmod \family default \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset addressmod \end_layout \end_inset \family typewriter setb0 spaceb0; // Declare a named address space called spaceb0 that uses setb0() \begin_inset Newline newline \end_inset __addressmod setb1 spaceb1; // Declare a named address space called spaceb1 that uses setb1() \begin_inset Newline newline \end_inset spaceb0 int x; // An int in address space spaceb0 \begin_inset Newline newline \end_inset spaceb1 int *y; // A pointer to an int in address space spaceb1 \begin_inset Newline newline \end_inset spaceb0 int *spaceb1 z; // A pointer in address space spaceb1 that points to an int in address space spaceb0 \end_layout \begin_layout Standard Non-intrinsic named address spaces for data in ROM are declared using the const keyword: \end_layout \begin_layout Verse \family typewriter void setb0(void); // The function that sets the currently active memory bank to b0 \begin_inset Newline newline \end_inset void setb1(void); // The function that sets the currently active memory bank to b1 \begin_inset Newline newline \end_inset __addressmod \family default \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset addressmod \end_layout \end_inset \family typewriter setb0 const spaceb0; // Declare a named address space called spaceb0 that uses setb0() and resides in ROM \begin_inset Newline newline \end_inset __addressmod setb1 spaceb1; // Declare a named address space called spaceb1 that uses setb1() and resides in RAM \begin_inset Newline newline \end_inset const spaceb0 int x = 42; // An int in address space spaceb0 \begin_inset Newline newline \end_inset spaceb1 int *y; // A pointer to an int in address space spaceb1 \begin_inset Newline newline \end_inset const spaceb0 int *spaceb1 z; // A pointer in address space spaceb1 that points to a constant int in address space spaceb0 \end_layout \begin_layout Standard Variables in non-intrinsic named address spaces will be placed in areas of the same name (this can be used for the placement of named address spaces in memory by the linker). \end_layout \begin_layout Standard SDCC will automatically insert calls to the corresponding function before accessing the variable. SDCC inserts the minimum possible number calls to the bank selection functions. See Philipp Klaus Krause, \begin_inset Quotes sld \end_inset Optimal Placement of Bank Selection Instructions in Polynomial Time \begin_inset Quotes srd \end_inset for details on how this works. \end_layout \begin_layout Subsection Absolute Addressing \begin_inset Index idx status open \begin_layout Plain Layout Absolute addressing \end_layout \end_inset \end_layout \begin_layout Standard Data items can be assigned an absolute address with the \emph on __at \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset at \end_layout \end_inset
\emph default keyword, which can also be used in addition to a named address space, e.g.: \end_layout \begin_layout Verse \family typewriter __xdata __at (0x7ffe) unsigned int chksum; \end_layout \begin_layout Standard In the above example the variable chksum will be located at 0x7ffe and 0x7fff of the external ram. The compiler does \emph on not \emph default reserve any space for variables declared in this way \begin_inset Marginal status collapsed \begin_layout Plain Layout \series bold \begin_inset space ~ \end_inset ! \end_layout \end_inset (they are implemented with an equate in the assembler). Thus it is left to the programmer to make sure there are no overlaps with other variables that are declared without the absolute address. The assembler listing file (.lst \begin_inset Index idx status collapsed \begin_layout Plain Layout .lst \end_layout \end_inset ) and the linker output files (.rst \begin_inset Index idx status collapsed \begin_layout Plain Layout .rst \end_layout \end_inset ) and (.map \begin_inset Index idx status collapsed \begin_layout Plain Layout .map \end_layout \end_inset ) are good places to look for such overlaps. \end_layout \begin_layout Standard If however you provide an initializer \begin_inset Index idx status collapsed \begin_layout Plain Layout Variable initialization \end_layout \end_inset actual memory allocation will take place and overlaps will be detected by the linker. E.g.: \end_layout \begin_layout Verse \family typewriter __code __at (0x7ff0) char Id[5] = \begin_inset Quotes sld \end_inset SDCC \begin_inset Quotes srd \end_inset ; \end_layout \begin_layout Standard In the above example the variable Id will be located from 0x7ff0 to 0x7ff4 in code memory. \end_layout \begin_layout Standard In case of memory mapped I/O devices the keyword \emph on volatile \emph default has to be used to tell the compiler that accesses might not be removed: \end_layout \begin_layout Verse \family typewriter volatile \begin_inset Index idx status collapsed \begin_layout Plain Layout volatile \end_layout \end_inset __xdata \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset xdata (mcs51, ds390 named address space) \end_layout \end_inset __at \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset at \end_layout \end_inset (0x8000) unsigned char PORTA_8255; \end_layout \begin_layout Standard For some architectures (mcs51) array accesses are more efficient if an (xdata/fa r) array \family typewriter \size footnotesize \begin_inset Index idx status collapsed \begin_layout Plain Layout Aligned array \end_layout \end_inset \family default \size default starts at a block (256 byte) boundary \begin_inset Index idx status collapsed \begin_layout Plain Layout block boundary \end_layout \end_inset (section \begin_inset CommandInset ref LatexCommand ref reference "subsec:A-Step-by Assembler Introduction" \end_inset has an example). \begin_inset Newline newline \end_inset Absolute addresses can be specified for variables in all named address spaces, e.g.: \end_layout \begin_layout Verse \family typewriter __bit \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset bit \end_layout \end_inset __at \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset at \end_layout \end_inset (0x02) bvar; \end_layout \begin_layout Standard The above example will allocate the variable at offset 0x02 in the bit-addressab le space. There is no real advantage to assigning absolute addresses to variables in this manner, unless you want strict control over all the variables allocated. One possible use would be to write hardware portable code. For example, if you have a routine that uses one or more of the microcontroller I/O pins, and such pins are different for two different hardwares, you can declare the I/O pins in your routine using: \end_layout \begin_layout Verse \family typewriter extern volatile \begin_inset Index idx status collapsed \begin_layout Plain Layout volatile \end_layout \end_inset __bit MOSI; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* master out, slave in */ \begin_inset Newline newline \end_inset extern volatile __bit MISO; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* master in, slave out */ \begin_inset Newline newline \end_inset extern volatile __bit MCLK; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* master clock */ \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset /* Input and Output of a byte on a 3-wire serial bus. \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset If needed adapt polarity of clock, polarity of data and bit order \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset */ \begin_inset Newline newline \end_inset unsigned char spi_io(unsigned char out_byte) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset unsigned char i=8; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset do { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset MOSI = out_byte & 0x80; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset out_byte <<= 1; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset MCLK = 1; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* __asm nop __endasm; */ \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* for slow peripherals */ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset if(MISO) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset out_byte += 1; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset MCLK = 0; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset } while(--i); \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset return out_byte; \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard Then, someplace in the code for the first hardware you would use \end_layout \begin_layout Verse \family typewriter __bit __at \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset at \end_layout \end_inset (0x80) MOSI; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* I/O port 0, bit 0 */ \begin_inset Newline newline \end_inset __bit __at (0x81) MISO; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* I/O port 0, bit 1 */ \begin_inset Newline newline \end_inset __bit __at (0x82) MCLK; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* I/O port 0, bit 2 */ \end_layout \begin_layout Standard Similarly, for the second hardware you would use \end_layout \begin_layout Verse \family typewriter __bit __at (0x83) MOSI; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* I/O port 0, bit 3 */ \begin_inset Newline newline \end_inset __bit __at (0x91) MISO; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* I/O port 1, bit 1 */ \begin_inset Newline newline \end_inset __bit \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset bit \end_layout \end_inset __at (0x92) MCLK; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* I/O port 1, bit 2 */ \end_layout \begin_layout Standard and you can use the same hardware dependent routine without changes, as for example in a library. This is somehow similar to sbit, but only one absolute address has to be specified in the whole project. \end_layout \begin_layout Subsection Preserved register specification \end_layout \begin_layout Standard SDCC allows to specify preserved registers in function declarations, to enable further optimizations on calls to functions implemented in assembler. Example for the Z80 architecture specifying that a function will preserve register pairs bc and iy: \end_layout \begin_layout Verse \family typewriter void f(void) __preserves_regs(b, c, iyl, iyh); \end_layout \begin_layout Subsection Binary constants \begin_inset Index idx status open \begin_layout Plain Layout Binary constants \end_layout \end_inset \end_layout \begin_layout Standard SDCC supports the use of binary constants, such as 0b01100010. This feature is only enabled when the compiler is invoked using \begin_inset Flex Code status open \begin_layout Plain Layout --std-sdccxx \end_layout \end_inset . \end_layout \begin_layout Subsection Returning void \end_layout \begin_layout Standard SDCC allows functions to return expressions of type void. This feature is only enabled when the compiler is invoked using \begin_inset Flex Code status open \begin_layout Plain Layout --std-sdccxx \end_layout \end_inset . \end_layout \begin_layout Subsection Omitting promotion on arguments of vararg function (does not apply to pdk14, pdk15) \end_layout \begin_layout Standard Arguments to vararg functions are not promoted when explicitly cast. This feature is only enabled when the compiler is invoked using \begin_inset Flex Code status open \begin_layout Plain Layout --std-sdccxx \end_layout \end_inset . This breaks compability with the C standards, so linking code compiled with \begin_inset Flex Code status open \begin_layout Plain Layout --std-sdccxx \end_layout \end_inset with code compiled using \begin_inset Flex Code status open \begin_layout Plain Layout --std-cxx \end_layout \end_inset can result in failing programs when arguments to vararg functions are explicitl y cast. \end_layout \begin_layout Section Parameters \begin_inset Index idx status collapsed \begin_layout Plain Layout Parameters \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout function parameter \end_layout \end_inset and Local Variables \begin_inset Index idx status collapsed \begin_layout Plain Layout local variables \end_layout \end_inset \begin_inset CommandInset label LatexCommand label name "sec:Parameters-and-Local-Variables" \end_inset \end_layout \begin_layout Standard Automatic (local) variables and parameters to functions are placed on the stack for most targets. For MCS51/DS390/HC08/S08 they can either be placed on the stack or in data-spac e. The default action of the compiler is to place these variables in the internal RAM (for small model) or external RAM (for medium or large model). This in fact makes them similar to \emph on static \begin_inset Index idx status collapsed \begin_layout Plain Layout static \end_layout \end_inset \emph default so by default functions are non-reentrant \begin_inset Index idx status collapsed \begin_layout Plain Layout reentrant \end_layout \end_inset . \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset They can be placed on the stack \begin_inset Index idx status collapsed \begin_layout Plain Layout stack \end_layout \end_inset by using the \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \end_layout \end_inset \emph default option, by using \emph on #pragma \begin_inset space ~ \end_inset stackauto \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma stackauto \end_layout \end_inset or by using the \emph on __reentrant \begin_inset Index idx status collapsed \begin_layout Plain Layout reentrant \end_layout \end_inset \emph default keyword in the function declaration, e.g.: \end_layout \begin_layout Verse \family typewriter unsigned char foo(char i) __reentrant \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard Since stack space on 8051 is limited, the \emph on __reentrant \emph default keyword or the \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \emph default option should be used sparingly. Note that the reentrant keyword just means that the parameters & local variables will be allocated to the stack, it \emph on does not \emph default mean that the function is register bank \begin_inset Index idx status collapsed \begin_layout Plain Layout register bank (mcs51, ds390) \end_layout \end_inset independent. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Local variables \begin_inset Index idx status collapsed \begin_layout Plain Layout local variables \end_layout \end_inset can be assigned intrinsic named address spaces and absolute \begin_inset Index idx status collapsed \begin_layout Plain Layout Absolute addressing \end_layout \end_inset addresses, e.g.: \end_layout \begin_layout Verse \family typewriter unsigned char foo(__xdata int parm) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __xdata unsigned char i; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __bit bvar; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __data __at \begin_inset Index idx status collapsed \begin_layout Plain Layout at \end_layout \end_inset (0x31) unsigned char j; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard In the above example the parameter \begin_inset Index idx status collapsed \begin_layout Plain Layout function parameter \end_layout \end_inset \emph on parm \emph default and the variable \emph on i \emph default will be allocated in the external ram, \emph on bvar \emph default in bit addressable space and \emph on j \emph default in internal ram. When compiled with \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \emph default or when a function is declared as \emph on reentrant \emph default this should only be done for static variables. \end_layout \begin_layout Standard It is however allowed to use bit parameters in reentrant functions and also non-static local bit variables are supported. Efficient use is limited to 8 semi-bitregisters in bit space. They are pushed and popped to stack \begin_inset Index idx status collapsed \begin_layout Plain Layout stack \end_layout \end_inset as a single byte just like the normal registers. \end_layout \begin_layout Section Overlaying \begin_inset CommandInset label LatexCommand label name "subsec:Overlaying" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Overlaying \end_layout \end_inset \end_layout \begin_layout Standard For non-reentrant \begin_inset Index idx status collapsed \begin_layout Plain Layout reentrant \end_layout \end_inset functions SDCC will try to reduce internal ram space usage by overlaying parameters and local variables of a function (if possible). Parameters and local variables \begin_inset Index idx status collapsed \begin_layout Plain Layout local variables \end_layout \end_inset of a function will be allocated to an overlayable segment if the function has \emph on no other function calls and the function is non-reentrant and the memory model \begin_inset Index idx status collapsed \begin_layout Plain Layout Memory model \end_layout \end_inset is small. \emph default If an explicit intrinsic named address space \begin_inset Index idx status open \begin_layout Plain Layout intrinsic named address space \end_layout \end_inset is specified for a local variable, it will NOT be overlaid. \end_layout \begin_layout Standard Note that the compiler (not the linkage editor) makes the decision for overlayin g the data items. Functions that are called from an interrupt service routine \begin_inset Marginal status collapsed \begin_layout Plain Layout \series bold ! \end_layout \end_inset should be preceded by a #pragma \begin_inset space ~ \end_inset nooverlay \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma nooverlay \end_layout \end_inset if they are not reentrant. \end_layout \begin_layout Standard Also note that the compiler does not do any processing of inline assembler code, so the compiler might incorrectly assign local variables and parameters of a function into the overlay segment if the inline assembler code calls other c-functions that might use the overlay. In that case the #pragma \begin_inset space ~ \end_inset nooverlay should be used. \end_layout \begin_layout Standard Parameters and local variables of functions that contain 16 or 32 bit multiplica tion \begin_inset Index idx status collapsed \begin_layout Plain Layout Multiplication \end_layout \end_inset or division \begin_inset Index idx status collapsed \begin_layout Plain Layout Division \end_layout \end_inset will NOT be overlaid since these are implemented using external functions, e.g.: \end_layout \begin_layout Verse \family typewriter #pragma save \begin_inset Newline newline \end_inset #pragma nooverlay \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma nooverlay \end_layout \end_inset \begin_inset Newline newline \end_inset void set_error(unsigned char errcd) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset P3 = errcd; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset #pragma restore \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset void some_isr () __interrupt \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt \end_layout \end_inset (2) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset set_error(10); \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard In the above example the parameter \emph on errcd \emph default for the function \emph on set_error \emph default would be assigned to the overlayable segment if the #pragma \begin_inset space ~ \end_inset nooverlay was not present, this could cause unpredictable runtime behaviour when called from an interrupt service routine. The #pragma \begin_inset space ~ \end_inset nooverlay ensures that the parameters and local variables for the function are NOT overlaid. \end_layout \begin_layout Section Interrupt Service Routines \begin_inset CommandInset label LatexCommand label name "subsec:Interrupt-Service-Routines" \end_inset \end_layout \begin_layout Subsection General Information \end_layout \begin_layout Standard SDCC allows \emph on i \emph default nterrupt \emph on s \emph default ervice \emph on r \emph default outines to be coded in C, with some extended keywords. \end_layout \begin_layout Verse \family typewriter void timer_isr (void) __interrupt (1) __using (1) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard The optional number following the \emph on __interrupt \begin_inset Index idx status open \begin_layout Plain Layout interrupt \end_layout \end_inset \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset interrupt \end_layout \end_inset \emph default keyword is the interrupt number this routine will service. When present, the compiler will insert a call to this routine in the interrupt vector table \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt vector table \end_layout \end_inset for the interrupt number specified. If you have multiple source files in your project, interrupt service routines can be present in any of them, but a prototype of the isr MUST be present or included in the file that contains the function \emph on main \emph default . The optional (8051 specific) keyword \emph on __using \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset using (mcs51, ds390 register bank) \end_layout \end_inset \emph default can be used to tell the compiler to use the specified register bank when generating code for this function. \begin_inset Newline newline \end_inset Interrupt service routines open the door for some very interesting bugs: \end_layout \begin_layout Subsubsection \begin_inset CommandInset label LatexCommand label name "subsec:Common-interrupt-pitfall-volatile" \end_inset Common interrupt pitfall: variable not declared \emph on volatile \end_layout \begin_layout Standard If an interrupt service routine changes variables which are accessed by other functions these variables have to be declared \emph on volatile \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout volatile \end_layout \end_inset . See \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://en.wikipedia.org/wiki/Volatile_variable \end_layout \end_inset . \end_layout \begin_layout Subsubsection \begin_inset CommandInset label LatexCommand label name "subsec:Common-interrupt-pitfall-non-atomic" \end_inset Common interrupt pitfall: \emph on non-atomic access \end_layout \begin_layout Standard If the access to these variables is not \emph on atomic \begin_inset Index idx status collapsed \begin_layout Plain Layout atomic \end_layout \end_inset \emph default (i.e. the processor needs more than one instruction for the access and could be interrupted while accessing the variable) the interrupt must be disabled during the access to avoid inconsistent data. \begin_inset Newline newline \end_inset Access to 16 or 32 bit variables is obviously not atomic on 8 bit CPUs and should be protected by disabling interrupts. You're not automatically on the safe side if you use 8 bit variables though. We need an example here: f.e. on the 8051 the harmless looking \begin_inset Quotes srd \end_inset \family typewriter flags \begin_inset space ~ \end_inset |= \begin_inset space ~ \end_inset 0x80; \family default \begin_inset Quotes sld \end_inset is not atomic if \family typewriter flags \family default resides in xdata. Setting \begin_inset Quotes srd \end_inset \family typewriter flags \begin_inset space ~ \end_inset |= \begin_inset space ~ \end_inset 0x40; \family default \begin_inset Quotes sld \end_inset from within an interrupt routine might get lost if the interrupt occurs at the wrong time. \begin_inset Quotes sld \end_inset \family typewriter counter \begin_inset space ~ \end_inset += \begin_inset space ~ \end_inset 8; \family default \begin_inset Quotes srd \end_inset is not atomic on the 8051 even if \family typewriter counter \family default is located in data memory. \begin_inset Newline newline \end_inset Bugs like these are hard to reproduce and can cause a lot of trouble. \end_layout \begin_layout Subsubsection \begin_inset CommandInset label LatexCommand label name "subsec:Common-interrupt-pitfall-stack-overflow" \end_inset Common interrupt pitfall: \emph on stack overflow \end_layout \begin_layout Standard The return address and the registers used in the interrupt service routine are saved on the stack \begin_inset Index idx status collapsed \begin_layout Plain Layout stack \end_layout \end_inset so there must be sufficient stack space. If there isn't variables or registers (or even the return address itself) will be corrupted. This \emph on stack overflow \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout stack overflow \end_layout \end_inset is most likely to happen if the interrupt occurs during the \begin_inset Quotes sld \end_inset deepest \begin_inset Quotes srd \end_inset subroutine when the stack is already in use for f.e. many return addresses. \end_layout \begin_layout Subsubsection \begin_inset CommandInset label LatexCommand label name "subsec:Common-interrupt-pitfall-non-reentrant" \end_inset Common interrupt pitfall: \emph on use of non-reentrant functions \end_layout \begin_layout Standard A special note here, integer multiplicative operators and floating-point \begin_inset Index idx status collapsed \begin_layout Plain Layout Floating point support \end_layout \end_inset operations might be implemented using external support routines, depending on the target architecture. If an interrupt service routine needs to do any of these operations on a target where functions are non-reentrant by default, then the support routines (as mentioned in a following section) will have to be recompiled using the \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \end_layout \end_inset \emph default option and the source file will need to be compiled using the \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -int-long-reent \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -int-long-reent \end_layout \end_inset compiler option. \begin_inset Newline newline \end_inset Note, the type promotion \begin_inset Index idx status collapsed \begin_layout Plain Layout type promotion \end_layout \end_inset required by ANSI C can cause 16 bit routines to be used \begin_inset Marginal status collapsed \begin_layout Plain Layout \series bold \begin_inset space ~ \end_inset ! \end_layout \end_inset without the programmer being aware of it. See f.e. the cast \family typewriter \series bold (unsigned char)(tail-1) \family default \series default \series bold within the if clause in section \begin_inset CommandInset ref LatexCommand ref reference "subsec:A-Step-by Assembler Introduction" \end_inset . \end_layout \begin_layout Standard Calling other functions from an interrupt service routine on a target where functions are non-reentrant by default is not recommended, avoid it if possible. Note that when some function is called from an interrupt service routine it should be preceded by a #pragma \begin_inset space ~ \end_inset nooverlay \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma nooverlay \end_layout \end_inset if it is not reentrant. Furthermore non-reentrant functions should not be called from the main program while the interrupt service routine might be active. They also must not be called from low priority interrupt service routines while a high priority interrupt service routine might be active. You could use semaphores or make the function \emph on critical \emph default if all parameters are passed in registers. \begin_inset Newline newline \end_inset Also see section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Overlaying" \end_inset \begin_inset space ~ \end_inset about Overlaying and section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Functions-using-private-banks" \end_inset \begin_inset space ~ \end_inset about Functions using private register banks. \end_layout \begin_layout Subsection MCS51/DS390 Interrupt Service Routines \end_layout \begin_layout Standard Interrupt \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt \end_layout \end_inset numbers and the corresponding address & descriptions for the Standard 8051/8052 are listed below. SDCC will automatically adjust the \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt vector table \end_layout \end_inset to the maximum interrupt number specified. \begin_inset Newline newline \end_inset \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout Interrupt # \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Vector Address \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout External 0 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0x0003 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Timer 0 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0x000b \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 2 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout External 1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0x0013 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 3 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Timer 1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0x001b \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 4 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Serial \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0x0023 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 5 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Timer 2 (8052) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0x002b \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout ... \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout ... \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout n \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0x0003 + 8*n \end_layout \end_inset \end_inset \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard If the interrupt service routine is defined without \emph on __using \begin_inset Index idx status collapsed \begin_layout Plain Layout using (mcs51, ds390 register bank) \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset using (mcs51, ds390 register bank) \end_layout \end_inset \emph default a register bank or with register bank 0 ( \emph on __using \emph default 0), the compiler will save the registers used by itself on the stack upon entry and restore them at exit, however if such an interrupt service routine calls another function then the entire register bank will be saved on the stack. This scheme may be advantageous for small interrupt service routines which have low register usage. \end_layout \begin_layout Standard If the interrupt service routine is defined to be using a specific register bank then only \emph on a, b, dptr \emph default & psw are saved and restored, if such an interrupt service routine calls another function (using another register bank) then the entire register bank of the called function will be saved on the stack \begin_inset Index idx status collapsed \begin_layout Plain Layout stack \end_layout \end_inset . This scheme is recommended for larger interrupt service routines. \end_layout \begin_layout Subsection HC08 \begin_inset Index idx status collapsed \begin_layout Plain Layout HC08 \end_layout \end_inset Interrupt Service Routines \end_layout \begin_layout Standard Since the number of interrupts \begin_inset Index idx status collapsed \begin_layout Plain Layout HC08!interrupt \end_layout \end_inset available is chip specific and the interrupt vector table always ends at the last byte of memory, the interrupt numbers corresponds to the interrupt vectors in reverse order of address. For example, interrupt 1 will use the interrupt vector at 0xfffc, interrupt 2 will use the interrupt vector at 0xfffa, and so on. However, interrupt 0 (the reset vector at 0xfffe) is not redefinable in this way; instead see section \begin_inset CommandInset ref LatexCommand ref reference "subsec:MCS51-Startup-Code" \end_inset for details on customizing startup. \end_layout \begin_layout Subsection Z80 and Z180 Interrupt Service Routines \end_layout \begin_layout Standard The Z80 \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80 \end_layout \end_inset uses several different methods for determining the correct interrupt \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80!interrupt \end_layout \end_inset vector depending on the hardware implementation. Therefore, SDCC does not attempt to generate an interrupt vector table. \end_layout \begin_layout Standard By default, SDCC generates code for a maskable interrupt, which uses a RETI instruction to return from the interrupt. To write an interrupt handler for the non-maskable interrupt, which needs a RETN instruction instead, leave out the interrupt number: \end_layout \begin_layout Verse \family typewriter void nmi_isr (void) __critical __interrupt \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard Since interrupts on the Z80 and Z180 are level-triggered (except for the NMI), interruptible interrupt handlers should only be used where hardware acknowledge is available. \end_layout \begin_layout Standard \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout Type \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Syntax \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Behaviour \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Interruptible interrupt handler \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout void f(void) __interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Interrupt handler can be interrupted by further interrupts \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Non-interruptible interrupt handler \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout void f(void) __critical __interrupt(0) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Interrupt handler can be interrupted by NMI only \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout NMI handler \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout void f(void) __critical __interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Interrupt handler can be interrupted by NMI only \end_layout \end_inset \end_inset \end_layout \begin_layout Subsection Rabbit 2000, 3000, 3000A and 4000 Interrupt Service Routines \end_layout \begin_layout Standard SDCC does not attempt to generate an interrupt vector table. \end_layout \begin_layout Standard \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout Type \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Syntax \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Behaviour \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Interruptible interrupt handler \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout void f(void) __interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Interrupt handler can be interrupted by further interrupts of same priority \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Non-interruptible interrupt handler \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout void f(void) __critical __interrupt(0) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Interrupt handler can be interrupted by interrupts of higher priority only \end_layout \end_inset \end_inset \end_layout \begin_layout Subsection GBZ80 and TLCS-90 Interrupt Service Routines \end_layout \begin_layout Standard SDCC does not attempt to generate an interrupt vector table. \end_layout \begin_layout Standard \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout Type \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Syntax \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Behaviour \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Interruptible interrupt handler \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout void f(void) __interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Interrupt handler can be interrupted by further interrupts \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Non-interruptible interrupt handler \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout void f(void) __critical __interrupt(0) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Interrupt handler cannot be interrupted by further interrupts \end_layout \end_inset \end_inset \end_layout \begin_layout Subsection STM8 Interrupt Service Routines \end_layout \begin_layout Standard The STM8 interrupt table contains 31 entries: Reset (used by SDCC for program startup), trap and user interrupts 0 to 29. Where the keyword \emph on __interrupt \begin_inset Index idx status open \begin_layout Plain Layout interrupt \end_layout \end_inset \emph default is used for normal user interrupts, the \emph on __trap \emph default keyword is used for the trap handler: \end_layout \begin_layout Verse \family typewriter void handler (void) __trap \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset } \end_layout \begin_layout Section Enabling and Disabling Interrupts \end_layout \begin_layout Subsection Critical Functions and Critical Statements \end_layout \begin_layout Standard A special keyword may be associated with a block or a function declaring it as \emph on __critical \emph default . SDCC will generate code to disable all interrupts \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt \end_layout \end_inset upon entry to a critical function and restore the interrupt enable to the previous state before returning. Nesting critical functions will need one additional byte on the stack \begin_inset Index idx status collapsed \begin_layout Plain Layout stack \end_layout \end_inset for each call. \end_layout \begin_layout Verse \family typewriter int foo () __critical \begin_inset Index idx status open \begin_layout Plain Layout critical \end_layout \end_inset \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset critical \end_layout \end_inset \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard The critical attribute maybe used with other attributes like \emph on reentrant. \emph default \begin_inset Newline newline \end_inset The keyword \emph on __critical \emph default may also be used to disable interrupts more locally: \end_layout \begin_layout Verse \family typewriter __critical{ i++; } \end_layout \begin_layout Standard More than one statement could have been included in the block. \end_layout \begin_layout Subsection Enabling and Disabling Interrupts directly \end_layout \begin_layout Standard Interrupts \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt \end_layout \end_inset can also be disabled and enabled directly (8051): \end_layout \begin_layout Verse \family typewriter EA = 0; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset or: \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset EA_SAVE = EA; \end_layout \begin_layout Verse \family typewriter ... \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset EA = 0; \end_layout \begin_layout Verse \family typewriter EA = 1; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \end_layout \begin_layout Verse \family typewriter \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset EA = EA_SAVE; \end_layout \begin_layout Standard On other architectures which have separate opcodes for enabling and disabling interrupts you might want to make use of defines with inline assembly \begin_inset Index idx status collapsed \begin_layout Plain Layout Assembler routines \end_layout \end_inset (HC08 \begin_inset Index idx status collapsed \begin_layout Plain Layout HC08!interrupt \end_layout \end_inset ): \end_layout \begin_layout Verse \family typewriter #define CLI __asm \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset asm \end_layout \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset cli \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __endasm \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset endasm \end_layout \end_inset ; \end_layout \begin_layout Verse \family typewriter #define SEI __asm \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sei \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __endasm; \end_layout \begin_layout Verse or for SDCC version 3.2.0 or newer: \end_layout \begin_layout Verse \family typewriter #define CLI asm ( \begin_inset Quotes sld \end_inset cli \begin_inset Quotes srd \end_inset ); \end_layout \begin_layout Verse \family typewriter #define SEI asm ( \begin_inset Quotes sld \end_inset sei \begin_inset Quotes srd \end_inset ); \end_layout \begin_layout Standard Note: it is sometimes sufficient to disable only a specific interrupt source like f.e. a timer or serial interrupt by manipulating an \emph on interrupt mask \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt mask \end_layout \end_inset \emph default register. \end_layout \begin_layout Standard Usually the time during which interrupts are disabled should be kept as short as possible. This minimizes both \emph on interrupt latency \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt latency \end_layout \end_inset (the time between the occurrence of the interrupt and the execution of the first code in the interrupt routine) and \emph on interrupt jitter \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt jitter \end_layout \end_inset (the difference between the shortest and the longest interrupt latency). These really are something different, f.e. a serial interrupt has to be served before its buffer overruns so it cares for the maximum interrupt latency, whereas it does not care about jitter. On a loudspeaker driven via a digital to analog converter which is fed by an interrupt a latency of a few milliseconds might be tolerable, whereas a much smaller jitter will be very audible. \end_layout \begin_layout Standard You can re-enable interrupts within an interrupt routine and on some architectur es you can make use of two (or more) levels of \emph on interrupt priorities \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt priority \end_layout \end_inset . On some architectures which don't support interrupt priorities these can be implemented by manipulating the interrupt mask and re-enabling interrupts within the interrupt routine. Check there is sufficient space on the stack \begin_inset Index idx status collapsed \begin_layout Plain Layout stack \end_layout \end_inset and don't add complexity unless you have to. \end_layout \begin_layout Subsection Semaphore \begin_inset Index idx status collapsed \begin_layout Plain Layout semaphore \end_layout \end_inset locking (mcs51/ds390) \end_layout \begin_layout Standard Some architectures (mcs51/ds390) have an atomic \begin_inset Index idx status collapsed \begin_layout Plain Layout atomic \end_layout \end_inset bit test and clear instruction. These type of instructions are typically used in preemptive multitasking systems, where a routine f.e. claims the use of a data structure ('acquires a lock \begin_inset Index idx status collapsed \begin_layout Plain Layout lock \end_layout \end_inset on it'), makes some modifications and then releases the lock when the data structure is consistent again. The instruction may also be used if interrupt and non-interrupt code have to compete for a resource. With the atomic bit test and clear instruction interrupts \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt \end_layout \end_inset don't have to be disabled for the locking operation. \end_layout \begin_layout Standard SDCC generates this instruction if the source follows this pattern: \end_layout \begin_layout Verse \family typewriter volatile \begin_inset Index idx status collapsed \begin_layout Plain Layout volatile \end_layout \end_inset bit resource_is_free; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset if (resource_is_free) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset resource_is_free=0; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset resource_is_free=1; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset } \end_layout \begin_layout Standard Note, mcs51 and ds390 support only an atomic \begin_inset Index idx status collapsed \begin_layout Plain Layout atomic \end_layout \end_inset bit test and \emph on clear \emph default instruction (as opposed to atomic bit test and \emph on set). \end_layout \begin_layout Section Functions using private register banks \begin_inset CommandInset label LatexCommand label name "subsec:Functions-using-private-banks" \end_inset (mcs51/ds390) \end_layout \begin_layout Standard Some architectures have support for quickly changing register sets. SDCC supports this feature with the \emph on __using \begin_inset Index idx status collapsed \begin_layout Plain Layout using (mcs51, ds390 register bank) \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset using (mcs51, ds390 register bank) \end_layout \end_inset \emph default attribute (which tells the compiler to use a register bank \begin_inset Index idx status collapsed \begin_layout Plain Layout register bank (mcs51, ds390) \end_layout \end_inset other than the default bank zero). It should only be applied to \emph on interrupt \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt \end_layout \end_inset \emph default functions (see footnote below). This will in most circumstances make the generated ISR code more efficient since it will not have to save registers on the stack. \end_layout \begin_layout Standard The \emph on __using \emph default attribute will have no effect on the generated code for a \emph on non-interrupt \emph default function (but may occasionally be useful anyway \begin_inset Foot status collapsed \begin_layout Plain Layout possible exception: if a function is called ONLY from 'interrupt' functions using a particular bank, it can be declared with the same 'using' attribute as the calling 'interrupt' functions. For instance, if you have several ISRs using bank one, and all of them call memcpy(), it might make sense to create a specialized version of memcpy() 'using 1', since this would prevent the ISR from having to save bank zero to the stack on entry and switch to bank zero before calling the function \end_layout \end_inset ). \begin_inset Newline newline \end_inset \emph on (pending: Note, nowadays the \emph default __using \emph on attribute has an effect on \emph default \emph on the generated code for a \emph default non-interrupt \emph on function \emph default . \emph on ) \end_layout \begin_layout Standard An \emph on interrupt \emph default function using a non-zero bank will assume that it can trash that register bank, and will not save it. Since high-priority interrupts \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupts \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt priority \end_layout \end_inset can interrupt low-priority ones on the 8051 and friends, this means that if a high-priority ISR \emph on using \emph default a particular bank occurs while processing a low-priority ISR \emph on using \emph default the same bank, terrible and bad things can happen. To prevent this, no single register bank should be \emph on used \emph default by both a high priority and a low priority ISR. This is probably most easily done by having all high priority ISRs use one bank and all low priority ISRs use another. If you have an ISR which can change priority at runtime, you're on your own: I suggest using the default bank zero and taking the small performance hit. \end_layout \begin_layout Standard It is most efficient if your ISR calls no other functions. If your ISR must call other functions, it is most efficient if those functions use the same bank as the ISR (see note 1 below); the next best is if the called functions use bank zero. It is very inefficient to call a function using a different, non-zero bank from an ISR. \end_layout \begin_layout Section Inline Assembler Code \begin_inset CommandInset label LatexCommand label name "sec:Inline-Assembler-Code" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Assembler routines \end_layout \end_inset \end_layout \begin_layout Subsection Inline Assembler Code Formats \end_layout \begin_layout Standard SDCC supports two formats for inline assembler code definition: \end_layout \begin_layout Subsubsection Old __asm ... __endasm; Format \end_layout \begin_layout Standard Most of inline assembler code examples in this manual use the old inline assembler code format, but the new format could be used equivalently. \end_layout \begin_layout Standard Example: \end_layout \begin_layout Verse \family typewriter __asm \family default \begin_inset Newline newline \end_inset \family typewriter \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; This is a comment \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset label: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset nop \begin_inset Newline newline \end_inset __endasm; \end_layout \begin_layout Subsubsection New __asm__ ( \begin_inset Quotes sld \end_inset inline_assembler_code \begin_inset Quotes srd \end_inset ) Format \end_layout \begin_layout Standard The __asm__ inline assembler code format was introduced in SDCC version 3.2.0. \end_layout \begin_layout Standard Example: \end_layout \begin_layout Verse \family typewriter __asm__ ( \begin_inset Quotes sld \end_inset ; This is a comment \backslash nlabel: \backslash n \backslash tnop \begin_inset Quotes srd \end_inset ); \end_layout \begin_layout Subsection A Step by Step Introduction \begin_inset CommandInset label LatexCommand label name "subsec:A-Step-by Assembler Introduction" \end_inset \end_layout \begin_layout Standard Starting from a small snippet of c-code this example shows for the MCS51 how to use inline assembly, access variables, a function parameter and an array in xdata memory. The example uses an MCS51 here but is easily adapted for other architectures. This is a buffer routine which should be optimized: \end_layout \begin_layout Verse \family typewriter \size footnotesize unsigned char __far \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset far (named address space) \end_layout \end_inset __at \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset at \end_layout \end_inset (0x7f00) buf[0x100]; \begin_inset Index idx status collapsed \begin_layout Plain Layout Aligned array \end_layout \end_inset \begin_inset Newline newline \end_inset unsigned char head, tail; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* if interrupts \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt \end_layout \end_inset are involved see \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Common-interrupt-pitfall-volatile" \end_inset about \family default \family typewriter \series bold volatile \family default \series default \family typewriter */ \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset void to_buffer( unsigned char c ) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset if( head != (unsigned char)(tail-1) ) \begin_inset space ~ \end_inset /* cast \family default \family typewriter \series bold needed \family default \series default \family typewriter to avoid promotion \begin_inset Index idx status collapsed \begin_layout Plain Layout promotion to signed int \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout type promotion \end_layout \end_inset to integer */ \begin_inset Marginal status collapsed \begin_layout Plain Layout \series bold \begin_inset space ~ \end_inset ! \end_layout \end_inset \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset buf[ head++ ] = c; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* access to a 256 byte aligned array */ \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard If the code snippet (assume it is saved in buffer.c) is compiled with SDCC then a corresponding buffer.asm file is generated. We define a new function \family typewriter to_buffer_asm() \family default in file buffer.c in which we cut and paste the generated code, removing unwanted comments and some ':'. Then add \begin_inset Quotes sld \end_inset \series bold __asm \series default \begin_inset Quotes srd \end_inset and \begin_inset Quotes sld \end_inset \series bold __endasm; \series default \begin_inset Quotes srd \end_inset \begin_inset Foot status collapsed \begin_layout Plain Layout Note, that the single underscore form (_asm and _endasm) are not C99 compatible, and for C99 compatibility, the double-underscore form (__asm and __endasm) has to be used. The latter is also used in the library functions. \end_layout \end_inset to the beginning and the end of the function body: \end_layout \begin_layout Verse \family typewriter \size footnotesize /* With a cut and paste from the .asm file, we have something to start with. \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset The function is not yet OK! (registers aren't saved) */ \begin_inset Newline newline \end_inset void to_buffer_asm( unsigned char c ) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __asm \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset asm \end_layout \end_inset \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset r2,dpl \begin_inset Newline newline \end_inset ;buffer.c if( head != (unsigned char)(tail-1) ) \begin_inset space ~ \end_inset /* cast \family default \family typewriter \series bold needed \family default \series default \family typewriter to avoid promotion \begin_inset Index idx status collapsed \begin_layout Plain Layout promotion to signed int \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout type promotion \end_layout \end_inset to integer */ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,_tail \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dec \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset r3,a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,_head \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset cjne a,ar3,00106$ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ret \begin_inset Newline newline \end_inset 00106$: \begin_inset Newline newline \end_inset ;buffer.c buf[ head++ ] = c; /* access to a 256 byte aligned array */ \begin_inset Index idx status collapsed \begin_layout Plain Layout Aligned array \end_layout \end_inset \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset r3,_head \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _head \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dpl,r3 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dph,#(_buf >> 8) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,r2 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset movx @dptr,a \begin_inset Newline newline \end_inset 00103$: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ret \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __endasm \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset endasm \end_layout \end_inset ; \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard The new file buffer.c should compile with only one warning about the unreferenced function argument 'c'. Now we hand-optimize the assembly code and insert an #define USE_ASSEMBLY (1) and finally have: \end_layout \begin_layout Verse \family typewriter \size footnotesize unsigned char __far __at(0x7f00) buf[0x100]; \begin_inset Newline newline \end_inset unsigned char head, tail; \begin_inset Newline newline \end_inset #define USE_ASSEMBLY (1) \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset #if !USE_ASSEMBLY \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset void to_buffer( unsigned char c ) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset if( head != (unsigned char)(tail-1) ) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset buf[ head++ ] = c; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset #else \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset void to_buffer( unsigned char c ) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset c; // to avoid warning: unreferenced function argument \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __asm \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset asm \end_layout \end_inset \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; save used registers here. \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; If we were still using r2,r3 we would have to push them here. \begin_inset Newline newline \end_inset ; if( head != (unsigned char)(tail-1) ) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset a,_tail \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dec \begin_inset space ~ \end_inset a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset xrl \begin_inset space ~ \end_inset a,_head \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; we could do an ANL a,#0x0f here to use a smaller buffer (see below) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset jz \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset t_b_end$ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; \begin_inset Newline newline \end_inset ; buf[ head++ ] = c; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset a,dpl \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; dpl holds lower byte of function argument \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset dpl,_head \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; buf is 0x100 byte aligned so head can be used directly \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset dph,#(_buf>>8) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset movx @dptr,a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc \begin_inset space ~ \end_inset _head \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; we could do an ANL _head,#0x0f here to use a smaller buffer (see above) \begin_inset Newline newline \end_inset t_b_end$: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; restore used registers here \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __endasm \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset endasm \end_layout \end_inset ; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset #endif \end_layout \begin_layout Standard The inline assembler code can contain any valid code understood by the assembler , this includes any assembler directives and comment lines. The assembler does not like some characters like ':' or ''' in comments. You'll find an 100+ pages assembler manual in sdcc/sdas/doc/asmlnk.txt \begin_inset Index idx status collapsed \begin_layout Plain Layout sdas (sdasgb, sdas6808, sdas8051, sdasz80) \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Assembler documentation \end_layout \end_inset or online at \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://svn.code.sf.net/p/sdcc/code/trunk/sdcc/sdas/doc/asmlnk.txt \end_layout \end_inset . \end_layout \begin_layout Standard The compiler does not do any validation of the code within the \family typewriter __asm \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset asm \end_layout \end_inset ... __endasm \size footnotesize \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset endasm \end_layout \end_inset \size default ; \family default keyword pair. Specifically it will not know which registers are used and thus register pushing/popping \begin_inset Index idx status collapsed \begin_layout Plain Layout push/pop \end_layout \end_inset has to be done manually. \end_layout \begin_layout Standard It is required that each assembly instruction be placed on a separate line. This is also recommended for labels (as the example shows). This is especially important to note when the inline assembler is placed in a C preprocessor macro as the preprocessor will normally put all replacing code on a single line. Only when the macro has each assembly instruction on a single line that ends with a line continuation character will it be placed as separate lines in the resulting .asm file. \end_layout \begin_layout Verse \family typewriter \size footnotesize #define \begin_inset space ~ \end_inset DELAY \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \backslash \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __asm \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \backslash \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset nop \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \backslash \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset nop \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \backslash \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __endasm \end_layout \begin_layout Standard When the - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset - \emph on peep-asm \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -peep-asm \end_layout \end_inset \emph default command line option is used, the inline assembler code will be passed through the peephole optimizer \begin_inset Index idx status collapsed \begin_layout Plain Layout Peephole optimizer \end_layout \end_inset . There are only a few (if any) cases where this option makes sense, it might cause some unexpected changes in the inline assembler code. Please go through the peephole optimizer rules defined in file \emph on peeph.def \emph default before using this option. \end_layout \begin_layout Subsection Naked Functions \begin_inset CommandInset label LatexCommand label name "subsec:Naked-Functions" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Naked functions \end_layout \end_inset \end_layout \begin_layout Standard A special keyword may be associated with a function declaring it as \emph on __naked \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset naked \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset naked \end_layout \end_inset . \emph default The \emph on _naked \emph default function modifier attribute prevents the compiler from generating prologue \begin_inset Index idx status collapsed \begin_layout Plain Layout function prologue \end_layout \end_inset and epilogue \begin_inset Index idx status collapsed \begin_layout Plain Layout function epilogue \end_layout \end_inset code for that function. This means that the user is entirely responsible for such things as saving any registers that may need to be preserved, selecting the proper register bank, generating the \emph on return \emph default instruction at the end, etc. Practically, this means that the contents of the function must be written in inline assembler. This is particularly useful for interrupt functions, which can have a large (and often unnecessary) prologue/epilogue. For example, compare the code generated by these two functions: \end_layout \begin_layout Verse \family typewriter volatile \begin_inset Index idx status collapsed \begin_layout Plain Layout volatile \end_layout \end_inset data unsigned char counter; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset void simpleInterrupt(void) __interrupt \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset interrupt \end_layout \end_inset (1) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset counter++; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset void nakedInterrupt(void) __interrupt (2) __naked \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __asm \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset asm \end_layout \end_inset \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _counter ; does not change flags, no need to save psw \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset reti \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; MUST explicitly include ret or reti in _naked function. \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __endasm \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset endasm \end_layout \end_inset ; \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard For an 8051 target, the generated simpleInterrupt looks like: \end_layout \begin_layout Verse \family typewriter Note, this is an \family default \family typewriter \emph on outdated \family default \emph default \family typewriter example, recent versions of SDCC generate \begin_inset Newline newline \end_inset the \family default \family typewriter \emph on same \family default \emph default \family typewriter code for simpleInterrupt() and nakedInterrupt()! \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset _simpleInterrupt: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset push \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset acc \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset push \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset b \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset push \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dpl \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset push \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dph \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset push \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset psw \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset psw,#0x00 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _counter \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset pop \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset psw \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset pop \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dph \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset pop \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dpl \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset pop \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset b \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset pop \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset acc \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset reti \end_layout \begin_layout Standard whereas nakedInterrupt looks like: \end_layout \begin_layout Verse \family typewriter _nakedInterrupt: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _counter ; does not change flags, no need to save psw \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset reti \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; MUST explicitly include ret or reti in _naked function \end_layout \begin_layout Standard The related directive #pragma exclude \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma exclude \end_layout \end_inset allows a more fine grained control over pushing & popping \begin_inset Index idx status collapsed \begin_layout Plain Layout push/pop \end_layout \end_inset the registers. \end_layout \begin_layout Standard While there is nothing preventing you from writing C code inside a \family typewriter _naked \family default function, there are many ways to shoot yourself in the foot doing this, and it is recommended that you stick to inline assembler. \end_layout \begin_layout Subsection Use of Labels within Inline Assembler \end_layout \begin_layout Standard SDCC allows the use of in-line assembler with a few restrictions regarding labels. All labels defined within inline assembler code have to be of the form \emph on nnnnn$ \emph default where nnnnn is a number less than 100 (which implies a limit of utmost 100 inline assembler labels \emph on per function \emph default \noun on ) \noun default . \begin_inset Foot status collapsed \begin_layout Plain Layout This is a slightly more stringent rule than absolutely necessary, but stays always on the safe side. Labels in the form of nnnnn$ are local labels in the assembler, locality of which is confined within two labels of the standard form. The compiler uses the same form for labels within a function (but starting from nnnnn=00100); and places always a standard label at the beginning of a function, thus limiting the locality of labels within the scope of the function. So, if the inline assembler part would be embedded into C-code, an improperly placed non-local label in the assembler would break up the reference space for labels created by the compiler for the C-code, leading to an assembling error. \end_layout \begin_layout Plain Layout The numeric part of local labels does not need to have 5 digits (although this is the form of labels output by the compiler), any valid integer will do. Please refer to the assemblers documentation for further details. \end_layout \end_inset \end_layout \begin_layout Verse \family typewriter __asm \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset asm \end_layout \end_inset \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset b,#10 \begin_inset Newline newline \end_inset 00001$: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset djnz \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset b,00001$ \begin_inset Newline newline \end_inset __endasm \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset endasm \end_layout \end_inset ; \end_layout \begin_layout Standard Inline assembler code cannot reference any C-labels, however it can reference labels \begin_inset Index idx status collapsed \begin_layout Plain Layout Labels \end_layout \end_inset defined by the inline assembler, e.g.: \end_layout \begin_layout Verse \family typewriter foo() { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* some c code */ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __asm \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; some assembler code \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ljmp 0003$ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __endasm; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* some more c code */ \begin_inset Newline newline \end_inset clabel: \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* inline assembler cannot reference this label */ \begin_inset Foot status collapsed \begin_layout Plain Layout Here, the C-label \family typewriter clabel \family default is translated by the compiler into a local label, so the locality of labels within the function is not broken. \end_layout \end_inset \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __asm \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 0003$: ;label (can be referenced by inline assembler only) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __endasm \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset endasm \end_layout \end_inset ; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* some more c code */ \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard In other words inline assembly code can access labels defined in inline assembly within the scope of the function. The same goes the other way, i.e. labels defines in inline assembly can not be accessed by C statements. \end_layout \begin_layout Section Support routines for integer multiplicative operators \end_layout \begin_layout Standard Depending on the target architecture, some integer multiplicative operators might be implemented by support routines. These support routines exist in portable C versions to facilitate porting to other MCUs, although depending on the target, assembler routines might be used instead. The following files contain some of the described routines, all of them can be found in /share/sdcc/lib. \begin_inset Newline newline \end_inset \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout \series bold Function \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold Description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout _mulint.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 16 bit multiplication \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout _divsint.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout signed 16 bit division (calls _divuint) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout _divuint.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout unsigned 16 bit division \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout _modsint.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout signed 16 bit modulus (calls _moduint) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout _moduint.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout unsigned 16 bit modulus \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout _mullong.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 32 bit multiplication \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout _divslong.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout signed 32 division (calls _divulong) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout _divulong.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout unsigned 32 division \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout _modslong.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout signed 32 bit modulus (calls _modulong) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout _modulong.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout unsigned 32 bit modulus \end_layout \end_inset \end_inset \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard In the mcs51, ds390, hc08, s08, pic14 and pic16 backends they are by default compiled as \emph on non-reentrant \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout reentrant \end_layout \end_inset ; when targeting on of these architectures, interrupt \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt \end_layout \end_inset service routines should not do any of the above operations. If this is unavoidable then the above routines will need to be compiled with the \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \end_layout \end_inset \emph default option, after which the source program will have to be compiled with \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -int-long-reent \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -int-long-reent \end_layout \end_inset \emph default option. Notice that you don't have to call these routines directly. The compiler will use them automatically every time an integer operation is required. \end_layout \begin_layout Section Floating Point Support \begin_inset Index idx status collapsed \begin_layout Plain Layout Floating point support \end_layout \end_inset \end_layout \begin_layout Standard SDCC supports (single precision 4 bytes) floating point numbers; the format is somewhat similar to IEEE, but it is not IEEE; in particular, denormalized floating -point numbers are not supported. The floating point support routines are derived from gcc's floatlib.c and consist of the following routines: \begin_inset Newline newline \end_inset \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \size footnotesize \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none Function \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _fsadd.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none add floating point numbers \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _fssub.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none subtract floating point numbers \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _fsdiv.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none divide floating point numbers \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _fsmul.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none multiply floating point numbers \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _fs2uchar.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none convert floating point to unsigned char \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _fs2char.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none convert floating point to signed char \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _fs2uint.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none convert floating point to unsigned int \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _fs2int.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none convert floating point to signed int \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _fs2ulong. \family default \series default \shape default \size default \emph default \bar default \noun default c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none convert floating point to unsigned long \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _fs2long.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none convert floating point to signed long \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _uchar2fs.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none convert unsigned char to floating point \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _char2fs.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none convert char to floating point number \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _uint2fs.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none convert unsigned int to floating point \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _int2fs.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none convert int to floating point numbers \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _ulong2fs.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none convert unsigned long to floating point number \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none _long2fs.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none convert long to floating point number \end_layout \end_inset \end_inset \begin_inset Newline newline \end_inset \end_layout \begin_layout Section Library Routines \begin_inset Index idx status collapsed \begin_layout Plain Layout Libraries \end_layout \end_inset \end_layout \begin_layout Standard \emph on \end_layout \begin_layout Subsection Compiler support routines (_gptrget, _mulint etc.) \end_layout \begin_layout Subsection Stdclib functions (puts, printf, strcat etc.) \end_layout \begin_layout Subsubsection \end_layout \begin_layout Paragraph getchar(), putchar() \end_layout \begin_layout Standard \begin_inset Index idx status collapsed \begin_layout Plain Layout \end_layout \end_inset As usual on embedded systems you have to provide your own \family typewriter getchar() \begin_inset Index idx status collapsed \begin_layout Plain Layout getchar() \end_layout \end_inset \family default and \family typewriter putchar() \begin_inset Index idx status collapsed \begin_layout Plain Layout putchar() \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout printf()!putchar() \end_layout \end_inset \family default routines. SDCC does not know whether the system connects to a serial line with or without handshake, LCD, keyboard or other device. And whether a \family typewriter lf \family default to \family typewriter crlf \family default conversion within \family typewriter putchar() \family default is intended. You'll find examples for serial routines f.e. in sdcc/device/lib. For the mcs51 this minimalistic polling \family typewriter putchar() \family default routine might be a start: \end_layout \begin_layout Verse \family typewriter int putchar (int c) { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset while (!TI) \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* assumes UART is initialized */ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset TI = 0; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset SBUF = c; \end_layout \begin_layout Verse \family typewriter \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset return c; \end_layout \begin_layout Verse \family typewriter } \end_layout \begin_layout Paragraph printf() \end_layout \begin_layout Standard The default \family typewriter printf() \begin_inset Index idx status collapsed \begin_layout Plain Layout printf() \end_layout \end_inset \family default implementation in \family typewriter printf_large.c \family default does not support float \begin_inset Index idx status collapsed \begin_layout Plain Layout Floating point support \end_layout \end_inset (except on ds390), only \begin_inset Index idx status collapsed \begin_layout Plain Layout \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout printf()!floating point support \end_layout \end_inset will be printed instead of the value. To enable floating point output, recompile it with the option \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset DUSE_FLOATS=1 \begin_inset Index idx status collapsed \begin_layout Plain Layout USE \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset FLOATS \end_layout \end_inset \emph default on the command line. Use \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-large \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-large \end_layout \end_inset \emph default for the mcs51 port, since this uses a lot of memory. To enable float support for the pic16 targets, see \begin_inset CommandInset ref LatexCommand ref reference "subsec:pic16Libraries" \end_inset . \end_layout \begin_layout Standard If you're short on code memory you might want to use \family typewriter printf_small() \begin_inset Index idx status collapsed \begin_layout Plain Layout printf()!printf \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset small() \end_layout \end_inset \family default \emph on instead \emph default of \family typewriter printf(). \family default For the mcs51 there additionally are assembly versions \family typewriter printf_tiny() \begin_inset Index idx status collapsed \begin_layout Plain Layout printf()!printf \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset tiny() (mcs51) \end_layout \end_inset \family default (subset of printf using less than 270 bytes) and \family typewriter printf_fast() \begin_inset Index idx status collapsed \begin_layout Plain Layout printf()!printf \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset fast() (mcs51) \end_layout \end_inset \family default and \family typewriter printf_fast_f() \begin_inset Index idx status collapsed \begin_layout Plain Layout printf()!printf \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset fast \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset f() (mcs51) \end_layout \end_inset \family default (floating-point aware version of printf_fast) which should fit the requirements of many embedded systems (printf_fast() can be customized by unsetting #defines to \emph on not \emph default support long variables and field widths). Be sure to use only one of these printf options within a project. \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard Feature matrix of different \emph on printf \emph default options on mcs51. \end_layout \begin_layout Standard \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout \series bold \size large mcs51 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout printf \begin_inset Index idx status collapsed \begin_layout Plain Layout printf() \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout printf \size scriptsize USE_FLOATS=1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout printf_small \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout printf_fast \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout printf_fast_f \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout printf_tiny \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout filename \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size scriptsize printf_large.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size scriptsize printf_large.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size scriptsize printfl.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size scriptsize printf_fast.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size scriptsize printf_fast_f.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size scriptsize printf_tiny.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \begin_inset Quotes sld \end_inset Hello World \begin_inset Quotes srd \end_inset size \end_layout \begin_layout Plain Layout small / large \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1.7k / 2.4k \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 4.3k / 5.6k \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1.2k / 1.8k \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1.3k / 1.3k \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1.9k / 1.9k \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0.44k / 0.44k \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout code size \end_layout \begin_layout Plain Layout small / large \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1.4k / 2.0k \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 2.8k / 3.7k \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0.45k / 0.47k (+ _ltoa) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1.2k / 1.2k \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1.6k / 1.6k \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0.26k / 0.26k \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout formats \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout cdi \emph on o \emph default psux \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none cd \family default \series default \shape default \size default \emph default \bar default \noun default f \family roman \series medium \shape up \size normal \emph off \bar no \noun off i \family default \series default \shape default \size default \emph on \bar default \noun default o \family roman \series medium \shape up \size normal \emph off \bar no \noun off psux \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout c \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none d \family default \series default \shape default \size default \emph on \bar default \noun default o \family roman \series medium \shape up \size normal \emph off \bar no \noun off s \family default \series default \shape default \size default \emph default \bar default \noun default x \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout cdsux \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout cdfsux \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout cdsux \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout long (32 bit) support \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout x \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout x \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout x \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout x \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none x \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout byte arguments on stack \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout b \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout b \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout float format \begin_inset Index idx status collapsed \begin_layout Plain Layout Floating point support \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout %f \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout %f \begin_inset Foot status collapsed \begin_layout Plain Layout Range limited to +/- 4294967040, precision limited to 8 digits past decimal \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout float formats %e %g \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout field width \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout x \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout x \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout x \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout x \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout string speed \begin_inset Foot status collapsed \begin_layout Plain Layout Execution time of printf("%s%c%s%c%c%c", "Hello", ' ', "World", '!', ' \backslash r', ' \backslash n'); standard 8051 @ 22.1184 MHz, empty putchar() \end_layout \end_inset , \end_layout \begin_layout Plain Layout small / large \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1.52 / 2.59 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1.53 / 2.62 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0.92 / 0.93 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0.45 / 0.45 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0.46 / 0.46 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0.45 / 0.45 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout int speed \begin_inset Foot status collapsed \begin_layout Plain Layout Execution time of printf("%d", -12345); standard 8051 @ 22.1184 MHz, empty putchar() \end_layout \end_inset , \end_layout \begin_layout Plain Layout small / large \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 3.01 / 3.61 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 3.01 / 3.61 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 3.51 / 18.13 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0.22 / 0.22 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0.23 / 0.23 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0.25 / 0.25 ms \begin_inset Foot status collapsed \begin_layout Plain Layout printf_tiny integer speed is data dependent, worst case is 0.33 ms \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout long speed \begin_inset Foot status collapsed \begin_layout Plain Layout Execution time of printf("%ld", -123456789); standard 8051 @ 22.1184 MHz, empty putchar() \end_layout \end_inset , \end_layout \begin_layout Plain Layout small / large \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 5.37 / 6.31 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 5.37 / 6.31 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 8.71 / 40.65 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0.40 / 0.40 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0.40 / 0.40 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout float speed \begin_inset Foot status collapsed \begin_layout Plain Layout Execution time of printf("%.3f", -12345.678); standard 8051 @ 22.1184 MHz, empty putchar() \end_layout \end_inset , \end_layout \begin_layout Plain Layout small / large \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 7.49 / 22.47 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1.04 / 1.04 ms \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout - \end_layout \end_inset \end_inset \end_layout \begin_layout Subsubsection \begin_inset Index idx status collapsed \begin_layout Plain Layout malloc.h \end_layout \end_inset \end_layout \begin_layout Standard As of SDCC 2.6.2 you no longer need to call an initialization routine before using dynamic memory allocation \begin_inset Index idx status collapsed \begin_layout Plain Layout dynamic memory allocation (malloc) \end_layout \end_inset and a default heap \begin_inset Index idx status collapsed \begin_layout Plain Layout heap (malloc) \end_layout \end_inset space of 1024 bytes is provided for malloc to allocate memory from. If you need a different heap size you need to recompile _heap.c with the required size defined in HEAP_SIZE. It is recommended to make a copy of this file into your project directory and compile it there with: \end_layout \begin_layout Verse \family typewriter sdcc -c _heap.c -D HEAP_SIZE=2048 \end_layout \begin_layout Standard And then link it with: \end_layout \begin_layout Verse \family typewriter sdcc main.rel _heap.rel \end_layout \begin_layout Subsection Math functions (sinf, powf, sqrtf etc.) \end_layout \begin_layout Subsubsection \end_layout \begin_layout Standard See definitions in file . \end_layout \begin_layout Subsection Other libraries \end_layout \begin_layout Standard Libraries \begin_inset Index idx status collapsed \begin_layout Plain Layout Libraries \end_layout \end_inset included in SDCC should have a license at least as liberal as the GPLv2+LE \begin_inset Index idx status collapsed \begin_layout Plain Layout GPLv2+LE \end_layout \end_inset . Exception are pic device libraries and header files which are derived from Microchip header (.inc) and linker script (.lkr) files. Microchip requires that "The header files should state that they are only to be used with authentic Microchip devices" which makes them incompatible with GPL. \end_layout \begin_layout Standard If you have ported some library or want to share experience about some code which f.e. falls into any of these categories Busses (I \begin_inset Formula $^{\textrm{2}}$ \end_inset C, CAN, Ethernet, Profibus, Modbus, USB, SPI, JTAG ...), Media (IDE, Memory cards, eeprom, flash...), En-/Decryption, Remote debugging, Realtime kernel, Keyboard, LCD, RTC, FPGA, PID then the sdcc-user mailing list \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/p/sdcc/mailman/sdcc-user/ \end_layout \end_inset would certainly like to hear about it. \end_layout \begin_layout Standard Programmers coding for embedded systems are not especially famous for being enthusiastic, so don't expect a big hurray but as the mailing list is searchabl e these references are very valuable. Let's help to create a climate where information is shared. \end_layout \begin_layout Section Memory Models \end_layout \begin_layout Subsection MCS51 Memory Models \begin_inset Index idx status collapsed \begin_layout Plain Layout Memory model \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout MCS51 memory model \end_layout \end_inset \end_layout \begin_layout Subsubsection Small, Medium, Large and Huge \end_layout \begin_layout Standard SDCC allows four memory models for MCS51 code, \shape slanted small, medium, large \shape default and \shape slanted huge \shape default . Modules compiled with different memory models should \emph on never \emph default be combined together or the results would be unpredictable. The library routines supplied with the compiler are compiled for all models (however, the libraries for –stack-auto are compiled for the small and large models only). The compiled library modules are contained in separate directories as small, medium, large and huge so that you can link to the appropriate set. \end_layout \begin_layout Standard When the medium, large or huge model is used all variables declared without specifying an intrinsic named address space will be allocated into the external ram, this includes all parameters and local variables (for non-reentra nt \begin_inset Index idx status collapsed \begin_layout Plain Layout reentrant \end_layout \end_inset functions). Medium model uses pdata and large and huge models use xdata. When the small model is used variables without an explicitly specified intrinsic named address space are allocated in the internal ram. \end_layout \begin_layout Standard The huge model compiles all functions as \emph on banked \begin_inset CommandInset ref LatexCommand ref reference "subsec:Bankswitching" \end_inset \emph default and is otherwise equal to large for now. All other models compile the functions without bankswitching by default. \end_layout \begin_layout Standard Judicious usage of the processor specific intrinsic named address spaces \begin_inset Index idx status open \begin_layout Plain Layout intrinsic named address space \end_layout \end_inset and the 'reentrant' function type will yield much more efficient code, than using the large model. Several optimizations are disabled when the program is compiled using the large model, it is therefore recommended that the small model be used unless absolutely required. \end_layout \begin_layout Subsubsection External Stack \begin_inset CommandInset label LatexCommand label name "subsec:External-Stack" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout stack \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout External stack (mcs51) \end_layout \end_inset \end_layout \begin_layout Standard The external stack (- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xstack option \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xstack \end_layout \end_inset ) is located in pdata \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset pdata (mcs51, ds390 named address space) \end_layout \end_inset memory (usually at the start of the external ram segment) and uses all unused space in pdata (max. 256 bytes). When - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xstack option is used to compile the program, the parameters and local variables \begin_inset Index idx status collapsed \begin_layout Plain Layout local variables \end_layout \end_inset of all reentrant functions are allocated in this area. This option is provided for programs with large stack space requirements. When used with the - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \end_layout \end_inset option, all parameters and local variables are allocated on the external stack (note: support libraries will need to be recompiled with the same options. There is a predefined target in the library makefile). \end_layout \begin_layout Standard The compiler outputs the higher order address byte of the external ram segment into port P2 \begin_inset Index idx status collapsed \begin_layout Plain Layout P2 (mcs51 sfr) \end_layout \end_inset (see also section \begin_inset CommandInset ref LatexCommand ref reference "subsec:MCS51-variants" \end_inset ), therefore when using the External Stack option, this port \emph on may not \emph default be used by the application program. \end_layout \begin_layout Subsection DS390 Memory Model \begin_inset Index idx status collapsed \begin_layout Plain Layout Memory model \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout DS390 memory model \end_layout \end_inset \end_layout \begin_layout Standard The only model supported is Flat 24 \begin_inset Index idx status collapsed \begin_layout Plain Layout Flat 24 (DS390 memory model) \end_layout \end_inset . This generates code for the 24 bit contiguous addressing mode of the Dallas DS80C390 part. In this mode, up to four meg of external RAM or code space can be directly addressed. See the data sheets at www.dalsemi.com for further information on this part. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Note that the compiler does not generate any code to place the processor into 24 bit mode (although \emph on tinibios \emph default in the ds390 libraries will do that for you). If you don't use \emph on tinibios \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout Tinibios (DS390) \end_layout \end_inset , the boot loader or similar code must ensure that the processor is in 24 bit contiguous addressing mode before calling the SDCC startup code. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Like the \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-large \emph default option, variables will by default be placed into the XDATA segment. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Segments may be placed anywhere in the 4 meg address space using the usual - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -*-loc options. Note that if any segments are located above 64K, the -r flag must be passed to the linker to generate the proper segment relocations, and the Intel HEX output format must be used. The -r flag can be passed to the linker by using the option \emph on -Wl-r \emph default on the SDCC command line. However, currently the linker can not handle code segments > 64k. \end_layout \begin_layout Subsection STM8 Memory Models \begin_inset Index idx status collapsed \begin_layout Plain Layout Memory model \end_layout \end_inset \begin_inset Index idx status open \begin_layout Plain Layout STM8 memory models \end_layout \end_inset \end_layout \begin_layout Standard SDCC implements two memory models for the STM8: \emph on medium \emph default (default) and \emph on large \emph default . Modules compiled with different memory models should \emph on never \emph default be combined together. The library routines supplied with the compiler are compiled for all models. \end_layout \begin_layout Standard In the medium model the address space is 16 bits for both objects and functions, allowing for a memory space of 64 KB. Since the STM8 typically has Flash starting at 0x8000, this means that only up to 32 KB of Flash can be used (most STM8 devices don't have more than 32 KB of Flash). \end_layout \begin_layout Standard In the large memory model, the address space is 16 bits for objects and 24 bits for functions. Since the STM8 typically has flash starting at 0x8000, this means that up to 32 KB of flash can be used for constant data, while the whole Flash can be used for functions. Code generated for the large model is slightly bigger and slower and needs slightly more stack space than code generated for the medium model. \end_layout \begin_layout Section Pragmas \begin_inset CommandInset label LatexCommand label name "sec:Pragmas" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Pragmas \end_layout \end_inset \end_layout \begin_layout Standard Pragmas are used to turn on and/or off certain compiler options. Some of them are closely related to corresponding command-line options (see section \begin_inset CommandInset ref LatexCommand vref reference "sec:Command-Line-Options" \end_inset ). \begin_inset Newline newline \end_inset Pragmas should be placed before and/or after a function, placing pragmas inside a function body could have unpredictable results. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset SDCC supports the following #pragma directives: \end_layout \begin_layout Itemize \series bold save \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma save \end_layout \end_inset - this will save most current options to the save/restore stack. See #pragma \begin_inset space ~ \end_inset restore. \end_layout \begin_layout Itemize \series bold restore \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma restore \end_layout \end_inset - will restore saved options from the last save. saves & restores can be nested. SDCC uses a save/restore stack: save pushes current options to the stack, restore pulls current options from the stack. See #pragma \begin_inset space ~ \end_inset save. \begin_inset Newline newline \end_inset \end_layout \begin_layout Itemize \series bold callee_saves \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma callee \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset saves \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout function prologue \end_layout \end_inset function1[,function2[,function3...]] \begin_inset CommandInset label LatexCommand label name "ite:callee_saves-function1[,function2[,function3...]]--" \end_inset - The compiler by default uses a caller saves convention for register saving across function calls, however this can cause unnecessary register pushing and popping \begin_inset Index idx status collapsed \begin_layout Plain Layout push/pop \end_layout \end_inset when calling small functions from larger functions. This option can be used to switch off the register saving convention for the function names specified. The compiler will not save registers when calling these functions, extra code need to be manually inserted at the entry and exit for these functions to save and restore the registers used by these functions, this can SUBSTANTIAL LY reduce code and improve run time performance of the generated code. In the future the compiler (with inter procedural analysis) may be able to determine the appropriate scheme to use for each function call. If - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -callee-saves command line option is used (see page \begin_inset CommandInset ref LatexCommand vpageref reference "lyx:--callee-saves-function1[,function2][,function3]..." \end_inset ), the function names specified in #pragma \begin_inset space ~ \end_inset callee_saves \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma callee \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset saves \end_layout \end_inset is appended to the list of functions specified in the command line. \end_layout \begin_layout Itemize \series bold exclude \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma exclude \end_layout \end_inset none | {acc[,b[,dpl[,dph[,bits]]]]} - The exclude pragma disables the generatio n of pairs of push/pop \begin_inset Index idx status collapsed \begin_layout Plain Layout push/pop \end_layout \end_inset instructions in \emph on I \emph default nterrupt \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt \end_layout \end_inset \emph on S \emph default ervice \emph on R \emph default outines. The directive should be placed immediately before the ISR function definition and it affects ALL ISR functions following it. To enable the normal register saving for ISR functions use #pragma \begin_inset space ~ \end_inset exclude \begin_inset space ~ \end_inset none \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma exclude \end_layout \end_inset . See also the related keyword \emph on __naked \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset naked \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset naked \end_layout \end_inset . \end_layout \begin_layout Itemize \series bold less_pedantic \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout pedantic \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma less \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset pedantic \end_layout \end_inset \begin_inset CommandInset label LatexCommand label name "ite:less_pedantic" \end_inset - the compiler will not warn you anymore for obvious mistakes, you're on your own now ;-(. See also the command line option - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -less-pedantic \begin_inset CommandInset ref LatexCommand vpageref reference "lyx:--less-pedantic" \end_inset . \begin_inset Newline newline \end_inset More specifically, the following warnings will be disabled: \shape italic comparison is always [true/false] due to limited range of data type \shape default (94); \shape italic overflow in implicit constant conversion \shape default (158); [the (in)famous] \shape italic conditional flow changed by optimizer: so said EVELYN the modified DOG \shape default (110); \shape italic function '[function name]' must return value \shape default (59). \begin_inset Newline newline \end_inset Furthermore, warnings of less importance (of PEDANTIC and INFO warning level) are disabled, too, namely: \shape italic constant value '[ \begin_inset Note Note status collapsed \begin_layout Plain Layout dunno what comes here - this warning appears to be unused altogether \end_layout \end_inset ]', out of range \shape default (81); \shape italic [left/right] shifting more than size of object changed to zero \shape default (116); \shape italic unreachable code \shape default (126); \shape italic integer overflow in expression \shape default (165); \shape italic unmatched #pragma save and #pragma restore \shape default (170); \shape italic comparison of 'signed char' with 'unsigned char' requires promotion to int \shape default (185); \shape italic ISO C90 does not support flexible array members \shape default (187); \shape italic extended stack by [number] bytes for compiler temp(s) :in function '[function \begin_inset space ~ \end_inset name]': \begin_inset space ~ \end_inset [ \begin_inset Note Note status collapsed \begin_layout Plain Layout appears to be always blank - what was supposed to be here? \end_layout \end_inset ] \shape default (114); \shape italic function '[function name]', # edges [number] , # nodes [number] , cyclomatic complexity [number] \shape default (121). \end_layout \begin_layout Itemize \series bold disable_warning \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma disable \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset warning \end_layout \end_inset - the compiler will not warn you anymore about warning number . \end_layout \begin_layout Itemize \series bold nogcse \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma nogcse \end_layout \end_inset - will stop global common subexpression elimination. \end_layout \begin_layout Itemize \series bold noinduction \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma noinduction \end_layout \end_inset - will stop loop induction optimizations. \end_layout \begin_layout Itemize \series bold noinvariant \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma noinvariant \end_layout \end_inset - will not do loop invariant optimizations. For more details see Loop Invariants in section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Loop-Optimizations" \end_inset . \end_layout \begin_layout Itemize \series bold noiv \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma noiv \end_layout \end_inset - Do not generate interrupt \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt \end_layout \end_inset vector table \begin_inset Index idx status collapsed \begin_layout Plain Layout interrupt vector table \end_layout \end_inset entries for all ISR functions defined after the pragma. This is useful in cases where the interrupt vector table must be defined manually, or when there is a secondary, manually defined interrupt vector table (e.g. for the autovector feature of the Cypress EZ-USB FX2). More elegantly this can be achieved by omitting the optional interrupt number after the \emph on __interrupt \emph default keyword, see section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Interrupt-Service-Routines" \end_inset \begin_inset space ~ \end_inset about interrupts. \end_layout \begin_layout Itemize \series bold noloopreverse \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma noloopreverse \end_layout \end_inset - Will not do loop reversal optimization \end_layout \begin_layout Itemize \series bold nooverlay \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma nooverlay \end_layout \end_inset - the compiler will not overlay the parameters and local variables of a function. \end_layout \begin_layout Itemize \series bold stackauto \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma stackauto \end_layout \end_inset - See option - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \end_layout \end_inset and section \begin_inset CommandInset ref LatexCommand ref reference "sec:Parameters-and-Local-Variables" \end_inset Parameters and Local Variables. \end_layout \begin_layout Itemize \series bold opt_code_speed \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma opt \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset code \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset speed \end_layout \end_inset - The compiler will optimize code generation towards fast code, possibly at the expense of code size. \end_layout \begin_layout Itemize \series bold opt_code_size \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma opt \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset code \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset size \end_layout \end_inset - The compiler will optimize code generation towards compact code, possibly at the expense of code speed. \end_layout \begin_layout Itemize \series bold opt_code_balanced \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma opt \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset code \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset balanced \end_layout \end_inset - The compiler will attempt to generate code that is both compact and fast, as long as meeting one goal is not a detriment to the other (this is the default). \end_layout \begin_layout Itemize \series bold std_sdcc89 \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma std \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset sdcc89 \end_layout \end_inset - Generally follow the C89 standard, but allow SDCC features that conflict with the standard. \end_layout \begin_layout Itemize \series bold std_c89 \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma std \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset c89 \end_layout \end_inset - Follow the C89 standard and disable SDCC features that conflict with the standard. \end_layout \begin_layout Itemize \series bold std_sdcc99 \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma std \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset sdcc99 \end_layout \end_inset - Generally follow the C99 standard, but allow SDCC features that conflict with the standard. \end_layout \begin_layout Itemize \series bold std_c99 \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma std \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset c99 \end_layout \end_inset - Follow the C99 standard and disable SDCC features that conflict with the standard. \end_layout \begin_layout Itemize \series bold codeseg \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma codeseg \end_layout \end_inset - Use this name (max. 8 characters) for the code segment. See option - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -codeseg. \end_layout \begin_layout Itemize \series bold constseg \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma constseg \end_layout \end_inset - Use this name (max. 8 characters) for the const segment. See option - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -constseg. \end_layout \begin_layout Standard The preprocessor \begin_inset Index idx status collapsed \begin_layout Plain Layout Preprocessor \end_layout \end_inset SDCPP \begin_inset Index idx status collapsed \begin_layout Plain Layout sdcpp (preprocessor) \end_layout \end_inset supports the following #pragma directives: \end_layout \begin_layout Itemize \series bold pedantic_parse_number \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout pedantic \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma pedantic \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset parse \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset number \end_layout \end_inset (+ | -) \begin_inset CommandInset label LatexCommand label name "ite:pedantic_parse_number" \end_inset - Pedantic parse numbers so that situations like 0xfe-LO_B(3) are parsed properly and the macro LO_B(3) gets expanded. Default is off. See also the - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -pedantic-parse-number command line option \begin_inset CommandInset ref LatexCommand vpageref reference "lyx:-pedantic-parse-number" \end_inset . \begin_inset Newline newline \end_inset Below is an example on how to use this pragma. \emph on Note: this functionality is not in conformance with standard! \end_layout \begin_layout Verse \family typewriter #pragma pedantic_parse_number + \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma pedantic \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset parse \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset number \end_layout \end_inset \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset #define LO_B(x) ((x) & 0xff) \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset unsigned char foo(void) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset unsigned char c=0xfe-LO_B(3); \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset return c; \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset \end_layout \begin_layout Itemize \series bold preproc_asm \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma preproc \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset asm \end_layout \end_inset (+ | -) - switch the __asm __endasm block preprocessing on / off. Default is on. Below is an example on how to use this pragma. \end_layout \begin_layout Verse \family typewriter #pragma preproc_asm - \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma preproc \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset asm \end_layout \end_inset \begin_inset Newline newline \end_inset /* this is a c code nop */ \begin_inset Newline newline \end_inset #define NOP ; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset void foo (void) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset while (--i) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset NOP \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __asm \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; this is an assembler nop instruction \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; it is not preprocessed to ';' since the asm preprocessing is disabled \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset NOP \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset __endasm; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset \end_layout \begin_layout Verse The pragma preproc_asm should not be used to define multilines of assembly code (even if it supports it), since this behavior is only a side effect of sdcpp __asm __endasm implementation in combination with pragma preproc_asm and is not in conformance with the C standard. This behavior might be changed in the future sdcpp versions. To define multilines of assembly code you have to include each assembly line into it's own __asm __endasm block. Below is an example for multiline assembly defines. \end_layout \begin_layout Verse \family typewriter #define Nop __asm \backslash \begin_inset Newline newline \end_inset nop \backslash \begin_inset Newline newline \end_inset __endasm \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset #define ThreeNops Nop; \backslash \begin_inset Newline newline \end_inset Nop; \backslash \begin_inset Newline newline \end_inset Nop \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset void foo (void) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ThreeNops; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset \end_layout \begin_layout Itemize \series bold sdcc_hash \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma sdcc \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset hash \end_layout \end_inset (+ | -) - Allow "naked" hash in macro definition, for example: \begin_inset Newline newline \end_inset \family typewriter #define DIR_LO(x) #(x & 0xff) \family default \begin_inset Newline newline \end_inset Default is off. Below is an example on how to use this pragma. \end_layout \begin_layout Verse \family typewriter #pragma preproc_asm + \begin_inset Newline newline \end_inset #pragma sdcc_hash + \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma sdcc \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset hash \end_layout \end_inset \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset #define ROMCALL(x) \backslash \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov R6_B3, #(x & 0xff) \backslash \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov R7_B3, #((x >> 8) & 0xff) \backslash \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset lcall __romcall \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset ... \begin_inset Newline newline \end_inset __asm \begin_inset Newline newline \end_inset ROMCALL(72) \begin_inset Newline newline \end_inset __endasm; \begin_inset Newline newline \end_inset ... \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard Some of the pragmas are intended to be used to turn-on or off certain optimizati ons which might cause the compiler to generate extra stack and/or data space to store compiler generated temporary variables. This usually happens in large functions. Pragma directives should be used as shown in the following example, they are used to control options and optimizations for a given function. \end_layout \begin_layout Verse \family typewriter #pragma save \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma save \end_layout \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* save the current settings */ \begin_inset Newline newline \end_inset #pragma nogcse \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma nogcse \end_layout \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* turnoff global subexpression elimination */ \begin_inset Newline newline \end_inset #pragma noinduction \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma noinduction \end_layout \end_inset /* turn off induction optimizations */ \begin_inset Newline newline \end_inset int foo () \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* large code */ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset #pragma restore \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma restore \end_layout \end_inset /* turn the optimizations back on */ \end_layout \begin_layout Standard The compiler will generate a warning message when extra space is allocated. It is strongly recommended that the save and restore pragmas be used when changing options for a function. \end_layout \begin_layout Section Defines Created by the Compiler \end_layout \begin_layout Standard Besides defines from the C standards, the compiler creates the following #defines \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset defines \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Defines created by the compiler \end_layout \end_inset : \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout \series bold #define \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold Description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!__SDCC (version macro) \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout version macro \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Always defined. Version number string (e.g. SDCC_3_2_0 for sdcc 3.2.0). \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SDCC \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout OBSOLETE. WILL BE REMOVED IN THE FUTURE. CURRENTLY Only defined for the mcs51 backend (and only if –std-cXX is not used). This macro has been available since SDCC 2.5.6 and is the version number as an int (ex. 256). PLEASE USE OTHER VERSION MACROS INSTEAD! \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_mcs51 \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!__SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset mcs51 \end_layout \end_inset or __SDCC_ds390 \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!__SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset ds390 \end_layout \end_inset or __SDCC_z80 \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!__SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset z80 \end_layout \end_inset , etc. \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout depending on the model used (e.g.: -mds390). Older versions used SDCC_mcs51, etc instead. \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_STACK_AUTO \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset STACK \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset AUTO \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout when \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto \emph default option is used \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_MODEL_SMALL \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset MODEL \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset SMALL \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout when \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-small \emph default is used \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_MODEL_MEDIUM \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset MODEL \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset MEDIUM \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout when \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-medium \emph default is used \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_MODEL_LARGE \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset MODEL \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset LARGE \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout when \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-large \emph default is used \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_MODEL_HUGE \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset MODEL \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset LARGE \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout when \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -model-huge \emph default is used \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_USE_XSTACK \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset USE \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset XSTACK \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout when \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -xstack \emph default option is used \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_STACK_TENBIT \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset STACK \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset TENBIT (ds390) \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout when \emph on -mds390 \emph default is used \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_MODEL_FLAT24 \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset MODEL \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset FLAT24 (ds390) \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout when \emph on -mds390 \emph default is used \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_VERSION_MAJOR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Always defined. SDCC major version number. E.g. 3 for SDCC 3.5.0 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_VERSION_MINOR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Always defined. SDCC minor version number. E.g. 5 for SDCC 3.5.0 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_VERSION_PATCH \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Always defined. SDCC patchlevel version number. E.g. 0 for SDCC 3.5.0 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_REVISION \begin_inset Index idx status open \begin_layout Plain Layout SDCC!Defines!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset REVISION (svn revision number) \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Always defined. SDCC svn revision number. Older versions of sdcc used SDCC_REVISION instead. \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SDCC_PARMS_IN_BANK1 \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset PARMS \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset IN \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset BANK1 \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout when \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -parms-in-bank1 \emph default is used \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_ALL_CALLEE_SAVES \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset ALL \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset CALLEE \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset SAVES \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout when \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -all-callee-saves \emph default is used \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_FLOAT_REENT \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset FLOAT \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset REENT \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout when \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -float-reent \emph default is used \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_INT_LONG_REENT \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset INT \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset LONG \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset REENT \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout when \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -int-long-reent \emph default is used \end_layout \end_inset \end_inset \end_layout \begin_layout Chapter Notes on supported Processors \end_layout \begin_layout Section MCS51 variants \begin_inset CommandInset label LatexCommand label name "subsec:MCS51-variants" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout MCS51 variants \end_layout \end_inset \end_layout \begin_layout Standard MCS51 processors are available from many vendors and come in many different flavours. While they might differ considerably in respect to Special Function Registers the core MCS51 is usually not modified or is kept compatible. \end_layout \begin_layout Subsection pdata access by SFR \end_layout \begin_layout Standard With the upcome of devices with internal xdata and flash memory devices using port P2 \begin_inset Index idx status collapsed \begin_layout Plain Layout P2 (mcs51 sfr) \end_layout \end_inset as dedicated I/O port is becoming more popular. Switching the high byte for __pdata \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset pdata (mcs51, ds390 named address space) \end_layout \end_inset access which was formerly done by port P2 is then achieved by a Special Function Register \begin_inset Index idx status collapsed \begin_layout Plain Layout sfr \end_layout \end_inset . In well-established MCS51 tradition the address of this \emph on sfr \emph default is where the chip designers decided to put it. Needless to say that they didn't agree on a common name either. So that the startup code can correctly initialize xdata variables, you should define an sfr with the name _XPAGE \family typewriter \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset XPAGE (mcs51) \end_layout \end_inset \family default at the appropriate location if the default, port P2, is not used for this. Some examples are: \end_layout \begin_layout Verse \family typewriter __sfr __at (0x85) _XPAGE; /* Ramtron VRS51 family a.k.a. MPAGE */ \end_layout \begin_layout Verse \family typewriter __sfr __at (0x92) _XPAGE; /* Cypress EZ-USB family, Texas Instruments (Chipcon) a.k.a. MPAGE */ \end_layout \begin_layout Verse \family typewriter __sfr __at (0x91) _XPAGE; /* Infineon (Siemens) C500 family a.k.a. XPAGE */ \end_layout \begin_layout Verse \family typewriter __sfr __at (0xaf) _XPAGE; /* some Silicon Labs (Cygnal) chips a.k.a. EMI0CN */ \end_layout \begin_layout Verse \family typewriter __sfr __at (0xaa) _XPAGE; /* some Silicon Labs (Cygnal) chips a.k.a. EMI0CN */ \end_layout \begin_layout Standard There are also devices without anything resembling _XPAGE, but luckily they usually have dual data-pointers. For these devices a different method can be used to correctly initialize xdata variables. A default implementation is already in crtxinit.asm but it needs to be assembled manually with DUAL_DPTR set to 1. \end_layout \begin_layout Standard For more exotic implementations further customizations may be needed. See section \begin_inset CommandInset ref LatexCommand ref reference "subsec:MCS51-Startup-Code" \end_inset for other possibilities. \end_layout \begin_layout Subsection Other Features available by SFR \end_layout \begin_layout Standard Some MCS51 variants offer features like Dual DPTR \begin_inset Index idx status collapsed \begin_layout Plain Layout DPTR \end_layout \end_inset , multiple DPTR, decrementing DPTR, 16x16 Multiply. These are currently not used for the MCS51 port. If you absolutely need them you can fall back to inline assembly or submit a patch to SDCC. \end_layout \begin_layout Subsection Bankswitching \begin_inset CommandInset label LatexCommand label name "subsec:Bankswitching" \end_inset \end_layout \begin_layout Standard Bankswitching \begin_inset Index idx status collapsed \begin_layout Plain Layout Bankswitching \end_layout \end_inset (a.k.a. code banking \begin_inset Index idx status collapsed \begin_layout Plain Layout code banking \end_layout \end_inset ) is a technique to increase the code space above the 64k limit of the 8051. \end_layout \begin_layout Subsubsection Hardware \end_layout \begin_layout Standard \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout 8000-FFFF \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout bank1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout bank2 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout bank3 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0000-7FFF \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout common \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SiLabs C8051F120 example \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \end_inset \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Usually the hardware uses some sfr (an output port or an internal sfr) to select a bank and put it in the banked area of the memory map. The selected bank usually becomes active immediately upon assignment to this sfr and when running inside a bank it will switch out this code it is currently running. Therefor you cannot jump or call directly from one bank to another and need to use a so-called trampoline in the common area. For SDCC an example trampoline is in crtbank.asm and you may need to change it to your 8051 derivative or schematic. The presented code is written for the C8051F120. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset When calling a banked function SDCC will put the LSB of the functions address in register R0, the MSB in R1 and the bank in R2 and then call this trampoline \emph on __sdcc_banked_call \emph default . The current selected bank is saved on the stack, the new bank is selected and an indirect jump is made. When the banked function returns it jumps to \emph on __sdcc_banked_ret \emph default which restores the previous bank and returns to the caller. \end_layout \begin_layout Subsubsection Software \end_layout \begin_layout Standard When writing banked software using SDCC you need to use some special keywords and options. You also need to take over a bit of work from the linker. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset To create a function that can be called from another bank it requires the keyword \emph on __banked \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout banked \end_layout \end_inset . The caller must see this in the prototype of the callee and the callee needs it for a proper return. Called functions within the same bank as the caller do not need the \emph on __banked \emph default keyword nor do functions in the common area. Beware: SDCC does not know or check if functions are in the same bank. This is your responsibility! \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Normally all functions you write end up in the segment CSEG. If you want a function explicitly to reside in the common area put it in segment HOME. This applies for instance to interrupt service routines as they should not be banked. \end_layout \begin_layout Standard Functions that need to be in a switched bank must be put in a named segment. The name can be mostly anything up to eight characters (e.g. BANK1). To do this you either use - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -codeseg BANK1 (See \begin_inset CommandInset ref LatexCommand ref reference "lyx:-codeseg" \end_inset ) on the command line when compiling or #pragma codeseg BANK1 (See \begin_inset CommandInset ref LatexCommand ref reference "sec:Pragmas" \end_inset ) at the top of the C source file. The segment name always applies to the whole source file and generated object so functions for different banks need to be defined in different source files. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset When linking your objects you need to tell the linker where to put your segments. To do this you use the following command line option to SDCC: -Wl-b BANK1=0x180 00 (See \begin_inset CommandInset ref LatexCommand ref reference "lyx:-Wl option" \end_inset ). This sets the virtual start address of this segment. It sets the banknumber to 0x01 and maps the bank to 0x8000 and up. The linker will not check for overflows, again this is your responsibility. \end_layout \begin_layout Subsection MCS51/DS390 Startup Code \begin_inset CommandInset label LatexCommand label name "subsec:MCS51-Startup-Code" \end_inset \end_layout \begin_layout Standard The compiler triggers the linker to link certain initialization modules from the runtime library \begin_inset Index idx status collapsed \begin_layout Plain Layout Runtime library \end_layout \end_inset called crt. Only the necessary ones are linked, for instance crtxstack.asm (GSINIT1, GSINIT5) is not linked unless the - \series bold \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \series default -xstack option is used. These modules are highly entangled by the use of special segments/areas, but a common layout is shown below: \end_layout \begin_layout Verse \family typewriter \series bold \size footnotesize (main.asm) \end_layout \begin_layout Verse \family typewriter \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .area HOME (CODE) \begin_inset Newline newline \end_inset __interrupt_vect: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ljmp __sdcc_gsinit_startup \end_layout \begin_layout Verse \family typewriter \series bold \size footnotesize (crtstart.asm) \end_layout \begin_layout Verse \family typewriter \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .area GSINIT0 (CODE) \begin_inset Newline newline \end_inset __sdcc_gsinit_startup:: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov sp,#__start__stack - 1 \end_layout \begin_layout Verse \family typewriter \series bold \size footnotesize (crtxstack.asm) \end_layout \begin_layout Verse \family typewriter \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .area GSINIT1 (CODE) \begin_inset Newline newline \end_inset __sdcc_init_xstack:: \begin_inset Newline newline \end_inset ; Need to initialize in GSINIT1 in case the user's __sdcc_external_startup uses the xstack. \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov __XPAGE,#(__start__xstack >> 8) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov _spx,#__start__xstack \end_layout \begin_layout Verse \family typewriter \series bold \size footnotesize (crtstart.asm) \end_layout \begin_layout Verse \family typewriter \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .area GSINIT2 (CODE) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset lcall __sdcc_external_startup \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,dpl \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset jz __sdcc_init_data \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ljmp __sdcc_program_startup \begin_inset Newline newline \end_inset __sdcc_init_data: \end_layout \begin_layout Verse \family typewriter \series bold \size footnotesize (crtxinit.asm) \end_layout \begin_layout Verse \family typewriter \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .area GSINIT3 (CODE) \begin_inset Newline newline \end_inset __mcs51_genXINIT:: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r1,#l_XINIT \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,r1 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset orl a,#(l_XINIT >> 8) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset jz 00003$ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r2,#((l_XINIT+255) >> 8) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov dptr,#s_XINIT \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r0,#s_XISEG \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov __XPAGE,#(s_XISEG >> 8) \begin_inset Newline newline \end_inset 00001$: \begin_inset space ~ \end_inset clr a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset movc a,@a+dptr \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset movx @r0,a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc dptr \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc r0 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset cjne r0,#0,00002$ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc __XPAGE \begin_inset Newline newline \end_inset 00002$: \begin_inset space ~ \end_inset djnz r1,00001$ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset djnz r2,00001$ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov __XPAGE,#0xFF \begin_inset Newline newline \end_inset 00003$: \end_layout \begin_layout Verse \family typewriter \series bold \size footnotesize (crtclear.asm) \end_layout \begin_layout Verse \family typewriter \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .area GSINIT4 (CODE) \begin_inset Newline newline \end_inset __mcs51_genRAMCLEAR:: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset clr a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r0,#(l_IRAM-1) \begin_inset Newline newline \end_inset 00004$: \begin_inset space ~ \end_inset mov @r0,a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset djnz r0,00004$ \begin_inset Newline newline \end_inset ; _mcs51_genRAMCLEAR() end \end_layout \begin_layout Verse \family typewriter \series bold \size footnotesize (crtxclear.asm) \end_layout \begin_layout Verse \family typewriter \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .area GSINIT4 (CODE) \begin_inset Newline newline \end_inset __mcs51_genXRAMCLEAR:: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r0,#l_PSEG \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,r0 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset orl a,#(l_PSEG >> 8) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset jz 00006$ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r1,#s_PSEG \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov __XPAGE,#(s_PSEG >> 8) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset clr a \begin_inset Newline newline \end_inset 00005$: \begin_inset space ~ \end_inset movx @r1,a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc r1 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset djnz r0,00005$ \begin_inset Newline newline \end_inset 00006$: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r0,#l_XSEG \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,r0 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset orl a,#(l_XSEG >> 8) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset jz 00008$ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r1,#((l_XSEG + 255) >> 8) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov dptr,#s_XSEG \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset clr a \begin_inset Newline newline \end_inset 00007$: \begin_inset space ~ \end_inset movx @dptr,a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc dptr \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset djnz r0,00007$ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset djnz r1,00007$ \begin_inset Newline newline \end_inset 00008$: \end_layout \begin_layout Verse \family typewriter \series bold \size footnotesize (crtxstack.asm) \end_layout \begin_layout Verse \family typewriter \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .area GSINIT5 (CODE) \begin_inset Newline newline \end_inset ; Need to initialize in GSINIT5 because __mcs51_genXINIT modifies __XPAGE \begin_inset Newline newline \end_inset ; and __mcs51_genRAMCLEAR modifies _spx. \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov __XPAGE,#(__start__xstack >> 8) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov _spx,#__start__xstack \end_layout \begin_layout Verse \family typewriter \series bold \size footnotesize (application modules) \end_layout \begin_layout Verse \family typewriter \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .area GSINIT (CODE) \end_layout \begin_layout Verse \family typewriter \series bold \size footnotesize (main.asm) \end_layout \begin_layout Verse \family typewriter \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .area GSFINAL (CODE) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ljmp __sdcc_program_startup \begin_inset Newline newline \end_inset ;-------------------------------------------------------- \begin_inset Newline newline \end_inset ; Home \begin_inset Newline newline \end_inset ;-------------------------------------------------------- \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .area HOME (CODE) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .area CSEG (CODE) \begin_inset Newline newline \end_inset __sdcc_program_startup: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset lcall _main \begin_inset Newline newline \end_inset ; return from main will lock up \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sjmp . \end_layout \begin_layout Standard One of these modules (crtstart.asm) contains a call to the C routine \emph on _sdcc_external_startup() \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset sdcc \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset external \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset startup() \end_layout \end_inset \emph default at the start of the CODE area. This routine is also in the runtime library \begin_inset Index idx status collapsed \begin_layout Plain Layout Runtime library \end_layout \end_inset and returns 0 by default. If this routine returns a non-zero value, the static & global variable initialization will be skipped and the function main will be invoked. Otherwise static & global variables will be initialized before the function main is invoked. You could add an \emph on _sdcc_external_startup() \emph default routine to your program to override the default if you need to setup hardware or perform some other critical operation prior to static & global variable initialization \begin_inset Index idx status collapsed \begin_layout Plain Layout Variable initialization \end_layout \end_inset . On some mcs51 variants __xdata \begin_inset Index idx status open \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status open \begin_layout Plain Layout \backslash _ \end_layout \end_inset xdata (mcs51, ds390 named address space \end_layout \end_inset memory has to be explicitly enabled before it can be accessed or if the watchdog \begin_inset Index idx status collapsed \begin_layout Plain Layout watchdog \end_layout \end_inset needs to be disabled, this is the place to do it. The startup code clears all internal data memory, 256 bytes by default, but from 0 to n-1 if \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -iram-size \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -iram-size \end_layout \end_inset n \emph default is used. (recommended for Chipcon CC1010). \end_layout \begin_layout Standard See also the compiler option \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-xinit \emph default - \emph on opt \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-xinit-opt \end_layout \end_inset and section \begin_inset CommandInset ref LatexCommand ref reference "subsec:MCS51-variants" \end_inset about MCS51-variants. \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard While these initialization modules are meant as generic startup code there might be the need for customization. Let's assume the return value of \emph on _sdcc_external_startup() \emph default in \emph on crtstart.asm \emph default should not be checked (or \emph on _sdcc_external_startup() \emph default should not be called at all). The recommended way would be to copy \emph on crtstart.asm \emph default (f.e. from \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://svn.code.sf.net/p/sdcc/code/trunk/sdcc/device/lib/mcs51/crtstart.asm \end_layout \end_inset ) into the source directory, adapt it there, then assemble it with \emph on sdas8051 -plosgff \begin_inset Foot status collapsed \begin_layout Plain Layout \begin_inset Quotes sld \end_inset -plosgff \begin_inset Quotes srd \end_inset are the assembler options used in \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.svn.sourceforge.net/viewvc/sdcc/trunk/sdcc/device/lib/mcs51/Makefile.in? view=markup \end_layout \end_inset \end_layout \end_inset crtstart.asm \emph default and when linking your project explicitly specify \emph on crtstart.rel \emph default . As a bonus a listing of the relocated object file \emph on crtstart.rst \emph default is generated. \end_layout \begin_layout Subsection Interfacing with Assembler Code \begin_inset Index idx status collapsed \begin_layout Plain Layout Assembler routines \end_layout \end_inset \end_layout \begin_layout Subsubsection Global Registers used for Parameter Passing \begin_inset Index idx status collapsed \begin_layout Plain Layout Parameter passing \end_layout \end_inset \end_layout \begin_layout Standard The compiler always uses the global registers \emph on DPL, DPH \begin_inset Index idx status collapsed \begin_layout Plain Layout DPTR, DPH, DPL \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout DPTR \end_layout \end_inset , B \begin_inset Index idx status collapsed \begin_layout Plain Layout B (mcs51, ds390 register) \end_layout \end_inset \emph default and \emph on ACC \begin_inset Index idx status collapsed \begin_layout Plain Layout ACC (mcs51, ds390 register) \end_layout \end_inset \emph default to pass the first (non-bit) parameter to a function, and also to pass the return value \begin_inset Index idx status collapsed \begin_layout Plain Layout return value \end_layout \end_inset of function; according to the following scheme: one byte return value in \emph on DPL \emph default , two byte value in \emph on DPL \emph default (LSB) and \emph on DPH \emph default (MSB). three byte values (generic pointers) in \emph on DPH \emph default , \emph on DPL \emph default and \emph on B \emph default , and four byte values in \emph on DPH \emph default , \emph on DPL \emph default , \emph on B \emph default and \emph on ACC \emph default . Generic pointers \begin_inset Index idx status collapsed \begin_layout Plain Layout generic pointer \end_layout \end_inset contain type of accessed memory in \emph on B \emph default : \series bold 0x00 \series default – xdata/far, \series bold 0x40 \series default – idata/near – , \series bold 0x60 \series default – pdata, \series bold 0x80 \series default – code \begin_inset Note Note status collapsed \begin_layout Plain Layout This might not be the case of certain memory models (medium???) \end_layout \end_inset . \end_layout \begin_layout Standard The second parameter onwards is either allocated on the stack (for reentrant routines or if - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-auto is used) or in data/xdata memory (depending on the memory model). \end_layout \begin_layout Standard Bit parameters are passed in a virtual register called 'bits' in bit-addressable space for reentrant functions or allocated directly in bit memory otherwise. \end_layout \begin_layout Standard Functions (with two or more parameters or bit parameters) that are called through function pointers \begin_inset Index idx status collapsed \begin_layout Plain Layout function pointers \end_layout \end_inset must therefor be reentrant so the compiler knows how to pass the parameters. \end_layout \begin_layout Subsubsection Register usage \end_layout \begin_layout Standard Unless the called function is declared as \family typewriter _naked \family default \begin_inset Index idx status collapsed \begin_layout Plain Layout naked \end_layout \end_inset , or the - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -callee-saves \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -callee-saves \end_layout \end_inset /- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -all-callee-saves command line option or the corresponding callee_saves pragma are used, the caller will save the registers ( \emph on R0-R7 \emph default ) around the call, so the called function can destroy they content freely. \end_layout \begin_layout Standard If the called function is not declared as \family typewriter _naked \family default , the caller will swap register banks around the call, if caller and callee use different register banks (having them defined by the \family typewriter __using \family default modifier). \end_layout \begin_layout Standard The called function can also use \emph on DPL \emph default , \emph on DPH \emph default , \emph on B \emph default and \emph on ACC \emph default observing that they are used for parameter/return value passing. \end_layout \begin_layout Subsubsection Assembler Routine (non-reentrant) \end_layout \begin_layout Standard In the following example \begin_inset Index idx status collapsed \begin_layout Plain Layout reentrant \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Assembler routines (non-reentrant) \end_layout \end_inset the function c_func calls an assembler routine asm_func, which takes two parameters \begin_inset Index idx status collapsed \begin_layout Plain Layout function parameter \end_layout \end_inset . \end_layout \begin_layout Verse \family typewriter extern int asm_func(unsigned char, unsigned char); \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset int c_func (unsigned char i, unsigned char j) \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset return asm_func(i,j); \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset int main() \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset return c_func(10,9); \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard The corresponding assembler function is: \end_layout \begin_layout Verse \family typewriter \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .globl _asm_func_PARM_2 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .globl _asm_func \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .area OSEG \begin_inset Newline newline \end_inset _asm_func_PARM_2: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .ds 1 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .area CSEG \begin_inset Newline newline \end_inset _asm_func: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,dpl \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset add \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,_asm_func_PARM_2 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dpl,a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dph \begin_inset Index idx status collapsed \begin_layout Plain Layout DPTR, DPH, DPL \end_layout \end_inset ,#0x00 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ret \end_layout \begin_layout Standard The parameter naming convention is __PARM_, where n is the parameter number starting from 1, and counting from the left. The first parameter is passed in \emph on DPH \emph default , \emph on DPL \emph default , \emph on B \emph default and \emph on ACC \emph default according to the description above. The variable name for the second parameter will be __PARM_2. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Assemble the assembler routine with the following command: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family sans \series bold sdas8051 -losg asmfunc.asm \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family default \series default Then compile and link the assembler routine to the C source file with the following command: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family sans \series bold sdcc cfunc.c asmfunc.rel \end_layout \begin_layout Subsubsection Assembler Routine (reentrant) \end_layout \begin_layout Standard In this case \begin_inset Index idx status collapsed \begin_layout Plain Layout reentrant \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Assembler routines (reentrant) \end_layout \end_inset the second parameter \begin_inset Index idx status collapsed \begin_layout Plain Layout function parameter \end_layout \end_inset onwards will be passed on the stack, the parameters are pushed from right to left i.e. before the call the second leftmost parameter will be on the top of the stack (the leftmost parameter is passed in registers). Here is an example: \end_layout \begin_layout Verse \family typewriter extern int asm_func(unsigned char, unsigned char, unsigned char) reentrant; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset int c_func (unsigned char i, unsigned char j, unsigned char k) reentrant \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset return asm_func(i,j,k); \begin_inset Newline newline \end_inset } \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset int main() \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset return c_func(10,9,8); \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard The corresponding (unoptimized) assembler routine is: \end_layout \begin_layout Verse \family typewriter .globl _asm_func \begin_inset Newline newline \end_inset _asm_func: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset push \begin_inset space ~ \end_inset _bp \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _bp,sp \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ;stack contains: _bp, return address, second parameter, third parameter \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset r2,dpl \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,_bp \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset add \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,#0xfd \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ;calculate pointer to the second parameter \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset r0,a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,_bp \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset add \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,#0xfc \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ;calculate pointer to the rightmost parameter \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset r1,a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,@r0 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset add \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,@r1 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset add \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,r2 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ;calculate the result (= sum of all three parameters) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dpl,a \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ;return value goes into dptr (cast into int) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dph,#0x00 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sp,_bp \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset pop \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _bp \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ret \end_layout \begin_layout Standard The compiling and linking procedure remains the same, however note the extra entry & exit linkage required for the assembler code, _bp is the stack frame pointer and is used to compute the offset into the stack for parameters and local variables. \end_layout \begin_layout Section DS400 port \end_layout \begin_layout Standard The DS80C400 \begin_inset Index idx status collapsed \begin_layout Plain Layout DS80C400 \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout DS400 \end_layout \end_inset microcontroller has a rich set of peripherals. In its built-in ROM library it includes functions to access some of the features, among them is a TCP stack with IP4 and IP6 support. Library headers (currently in beta status) and other files are provided at \size footnotesize \begin_inset Flex URL status collapsed \begin_layout Plain Layout ftp://ftp.dalsemi.com/pub/tini/ds80c400/c_libraries/sdcc/index.html \end_layout \end_inset . \end_layout \begin_layout Section The Z80, Z180, Rabbit 2000/3000, Rabbit 3000A, GBZ80, eZ80 and TLCS-90 ports \end_layout \begin_layout Standard SDCC can target the Z80 \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80 \end_layout \end_inset , Z180, Rabbit 2000/3000, Rabbit 3000A and LR35902, the Nintendo GameBoy's Z80-like gbz80 \begin_inset Index idx status collapsed \begin_layout Plain Layout gbz80 (GameBoy Z80) \end_layout \end_inset . \end_layout \begin_layout Standard When a frame pointer is used, it resides in IX. Register A, B, C, D, E, H, L and IY are used as a temporary registers for holding variables. Return values \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80!return value \end_layout \end_inset for the Z80 port are stored in L (one byte), HL (two bytes), or DEHL (four bytes). The gbz80 port use the same set of registers for the return values, but in a different order of significance: E (one byte), DE (two bytes), or HLDE (four bytes). \end_layout \begin_layout Standard When enabling optimizations using \begin_inset Flex Code status open \begin_layout Plain Layout --opt-code \end_layout \end_inset size and a sufficiently high value for \begin_inset Flex Code status open \begin_layout Plain Layout --max-allocs-per-node \end_layout \end_inset sdcc typically generates much better code for these architectures than many other compilers. A comparison of compilers for these architecture can be found at \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/wiki/index.php/Z80_code_size \end_layout \end_inset . \end_layout \begin_layout Subsection Startup Code \end_layout \begin_layout Standard On the Z80 \begin_inset Index idx status collapsed \begin_layout Plain Layout Z80 \end_layout \end_inset the startup code is inserted by linking with crt0.rel which is generated from sdcc/device/lib/z80/crt0.s. If you need a different startup code you can use the compiler option \emph on - \series bold \emph default \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \series default \emph on -no-std-crt0 \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-std-crt0 \end_layout \end_inset and provide your own crt0.rel. When using a custom crt0.rel it needs to be listed first when linking. \end_layout \begin_layout Subsection Complex instructions \end_layout \begin_layout Standard The Z80 and some derivatives support complex instructions, such as ldir, cpir, ... . SDCC only emits these instructions for functions in the standard library. Thus, e.g. copying one array into another is more efficient when using memcpy() than by using a a user-written loop. \end_layout \begin_layout Standard Depending on the target, code generation options and the parameters to the call, SDCC emits ldir for memcpy(), ldir or lsidr for memset(), ldi for strcpy(), ldi for strncpy(). Other library functions use the complex instructions as well, but for those, function calls are generated. \end_layout \begin_layout Subsection Calling conventions \end_layout \begin_layout Standard By default, all parameters are passed on the stack, right-to-left. 8-bit return values are passed in l, 16-bit values in hl, 32-bit values in dehl. Except for the GBZ80, where 8-bit values are passed in e, 16-bit values in de, 32-bit values in hlde. Larger return values are passed in memory in a location specified by the caller through a hidden pointer argument. \end_layout \begin_layout Standard There are three other calling conventions supported, which can be specified using the keywords __smallc, __z88dk_fastcall (not on GBZ80) and __z88dk_callee. They are primarily intended for compability with libraries written for other compilers. For __z88dk_fastcall, there may be only one parameter of at most 32 bits, which is passed the same way as the return value. For __z88dk_callee, parameters are passed on the stack, but the stack is not adjusted for the parameters after the call (thus the callee has to do this instead). __z88dk_callee is currently supported on the caller side only. __z88dk_callee can be combined with __smallc. \end_layout \begin_layout Subsection Small-C calling convention \end_layout \begin_layout Standard Functions declared as __smallc are called using the Small-C calling convention (passing arguments on-stack left-to-right, 1 byte arguments are passed as 2 bytes, with the value in the lower byte). This way assembler routines originally written for Small-C or code generated by Small-C can be called from SDCC. Currently variable arguments are not yet supported (neither on the caller nor on the callee side). \end_layout \begin_layout Subsection Unsafe reads \end_layout \begin_layout Standard Usually, Z80-based systems (except for the Gameboy) have separate I/O and memory spaces, and any memory location can be read without side-effects. For such systems, the option –allow-unsafe-reads can be used to enable some extra optimizations. \end_layout \begin_layout Section The HC08 and S08 ports \end_layout \begin_layout Standard The port to the Freescale/Motorola HC08 \begin_inset Index idx status collapsed \begin_layout Plain Layout HC08 \end_layout \end_inset and S08 does not yet generate code as compact as that generated by some non-free compilers. A comparison of compilers for these architecture can be found at \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/wiki/index.php/Hc08_code_size \end_layout \end_inset . \end_layout \begin_layout Subsection Startup Code \end_layout \begin_layout Standard The HC08 \begin_inset Index idx status collapsed \begin_layout Plain Layout HC08 \end_layout \end_inset startup code follows the same scheme as the MCS51 startup code. \end_layout \begin_layout Section The STM8 port \end_layout \begin_layout Subsection Calling convention \end_layout \begin_layout Standard Arguments are passed on the stack right-to-left. Return values are in a (8 bit), x (16 bit), xyl (24 bit), xy (32 bit) or use a hidden extra pointer parameter pointing to the location (anything wider than 32 bit). \end_layout \begin_layout Section The PIC14 \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC14 \end_layout \end_inset port \end_layout \begin_layout Standard The PIC14 port adds support for Microchip \begin_inset Index idx status collapsed \begin_layout Plain Layout Microchip \end_layout \end_inset \begin_inset Formula $^{\text{TM}}$ \end_inset PIC \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC14 \end_layout \end_inset \begin_inset Formula $^{\text{TM}}$ \end_inset MCUs with 14 bit wide instructions. This port is not yet mature and still lacks many features. However, it can work for simple code. \end_layout \begin_layout Standard \noindent Currently supported devices include: \end_layout \begin_layout Standard \begin_inset VSpace defskip \end_inset \end_layout \begin_layout Standard 10F320, 10F322, 10LF320, 10LF322 \end_layout \begin_layout Standard 12F609, 12F615, 12F617, 12F629, 12F635, 12F675, 12F683 \end_layout \begin_layout Standard 12F752 \end_layout \begin_layout Standard 12HV752 \end_layout \begin_layout Standard 16C62, 16C63A, 16C65B \end_layout \begin_layout Standard 16C71, 16C72, 16C73B, 16C74B \end_layout \begin_layout Standard 16C432, 16C433 \end_layout \begin_layout Standard 16C554, 16C557, 16C558 \end_layout \begin_layout Standard 16C620, 16C620A, 16C621, 16C621A, 16C622, 16C622A \end_layout \begin_layout Standard 16C710, 16C711, 16C715, 16C717, 16C745, 16C765, 16C770, 16C771, 16C773, 16C774, 16C781, 16C782 \end_layout \begin_layout Standard 16C925, 16C926 \end_layout \begin_layout Standard 16CR73, 16CR74, 16CR76, 16CR77 \end_layout \begin_layout Standard 16CR620A \end_layout \begin_layout Standard 16F72 ,16F73, 16F74, 16F76, 16F77 \end_layout \begin_layout Standard 16F84, 16F84A, 16F87, 16F88 \end_layout \begin_layout Standard 16F610, 16F616, 16F627, 16F627A, 16F628, 16F628A, 16F630, 16F631, 16F636, 16F639, 16F648A \end_layout \begin_layout Standard 16F676, 16F677, 16F684, 16F685, 16F687, 16F688, 16F689, 16F690 \end_layout \begin_layout Standard 16F707, 16F716, 16F720, 16F721, 16F722, 16F722A, 16F723, 16F723A, 16F724, 16F726, 16F727 \end_layout \begin_layout Standard 16F737, 16F747, 16F753, 16F767, 16F777, 16F785 \end_layout \begin_layout Standard 16F818, 16F819, 16F870, 16F871, 16F872, 16F873, 16F873A, 16F874, 16F874A, 16F876, 16F876A \end_layout \begin_layout Standard 16F877, 16F877A, 16F882, 16F883, 16F884, 16F886, 16F887 \end_layout \begin_layout Standard 16F913, 16F914, 16F916, 16F917, 16F946 \end_layout \begin_layout Standard 16LF74, 16LF76, 16LF77 \end_layout \begin_layout Standard 16LF84, 16LF84A, 16LF87, 16LF88 \end_layout \begin_layout Standard 16LF627, 16LF627A, 16LF628, 16LF628A, 16LF648A \end_layout \begin_layout Standard 16LF707, 16LF720, 16LF721, 16LF722, 16LF722A, 16LF723, 16LF723A, 16LF724, 16LF726, 16LF727 \end_layout \begin_layout Standard 16LF747, 16LF767, 16LF777 \end_layout \begin_layout Standard 16LF818, 16LF819, 16LF870, 16LF871, 16LF872, 16LF873, 16LF873A, 16LF874, 16LF874A \end_layout \begin_layout Standard 16LF876, 16LF876A, 16LF877, 16LF877A \end_layout \begin_layout Standard 16HV610, 16HV616, 16HV753, 16HV785 \end_layout \begin_layout Standard \begin_inset VSpace defskip \end_inset \end_layout \begin_layout Standard \noindent \align left Supported devices with enhanced cores: \end_layout \begin_layout Standard \begin_inset VSpace defskip \end_inset \end_layout \begin_layout Standard 12F1501, 12F1571, 12F1572, 12F1612, 12F1822, 12F1840 \end_layout \begin_layout Standard 12LF1501, 12LF1552, 12LF1571, 12LF1572, 12LF1612, 12LF1822, 12LF1840, 12LF1840T3 9A, 12LF1840T48A \end_layout \begin_layout Standard 16F1454, 16F1455, 16F1458, 16F1459 \end_layout \begin_layout Standard 16F1503, 16F1507, 16F1508, 16F1509, 16F1512, 16F1513, 16F1516, 16F1517, 16F1518, 16F1519 \end_layout \begin_layout Standard 16F1526, 16F1527, 16F1574, 16F1575, 16F1578, 16F1579 \end_layout \begin_layout Standard 16F1613, 16F1614, 16F1615, 16F1618, 16F1619 \end_layout \begin_layout Standard 16F1703, 16F1704, 16F1705, 16F1707, 16F1708, 16F1709, 16F1713, 16F1716, 16F1717, 16F1718, 16F1719 \end_layout \begin_layout Standard 16F1764, 16F1765, 16F1768, 16F1769, 16F1773, 16F1776, 16F1777, 16F1778, 16F1779 \end_layout \begin_layout Standard 16F1782, 16F1783, 16F1784, 16F1786, 16F1787, 16F1788, 16F1789 \end_layout \begin_layout Standard 16F1823, 16F1824, 16F1825, 16F1826, 16F1827, 16F1828, 16F1829, 16F1829LIN, 16F1847 \end_layout \begin_layout Standard 16F1933, 16F1934, 16F1936, 16F1937, 16F1938, 16F1939, 16F1946, 16F1947 \end_layout \begin_layout Standard 16F18313, 16F18323, 16F18324, 16F18325, 16F18344, 16F18345, \end_layout \begin_layout Standard 16F18855, 16F18875 \end_layout \begin_layout Standard 16LF1454, 16LF1455, 16LF1458, 16LF1459 \end_layout \begin_layout Standard 16LF1503, 16LF1507, 16LF1508, 16LF1509, 16LF1512, 16LF1513, 16LF1516, 16LF1517, 16LF1518, 16LF1519, \end_layout \begin_layout Standard 16LF1526, 16LF1527 \end_layout \begin_layout Standard 16LF1554, 16LF1559, 16LF1566, 16LF1567, 16LF1574, 16LF1575, 16LF1578, 16LF1579 \end_layout \begin_layout Standard 16LF1613, 16LF1614, 16LF1615, 16LF1618, 16LF1619 \end_layout \begin_layout Standard 16LF1703, 16LF1704, 16LF1705, 16LF1707, 16LF1708, 16LF1709, 16LF1713, 16LF1716, 16LF1717, 16LF1718, 16LF1719 \end_layout \begin_layout Standard 16LF1764, 16LF1765, 16LF1768, 16LF1769, 16LF1773, 16LF1776, 16LF1777, 16LF1778, 16LF1779 \end_layout \begin_layout Standard 16LF1782, 16LF1783, 16LF1784, 16LF1786, 16LF1787, 16LF1788, 16LF1789, \end_layout \begin_layout Standard 16LF1823, 16LF1824, 16LF1824T39A \end_layout \begin_layout Standard 16LF1825, 16LF1826, 16LF1827, 16LF1828, 16LF1829, 16LF1847 \end_layout \begin_layout Standard 16LF1902, 16LF1903, 16LF1904, 16LF1906, 16LF1907 \end_layout \begin_layout Standard 16LF1933, 16LF1934, 16LF1936, 16LF1937, 16LF1938, 16LF1939, 16LF1946, 16LF1947 \end_layout \begin_layout Standard 16LF18313, 16LF18323, 16LF18324, 16LF18325, 16LF18344, 16LF18345 \end_layout \begin_layout Standard 16LF18855, 16LF18875 \end_layout \begin_layout Standard \begin_inset VSpace defskip \end_inset \end_layout \begin_layout Standard \noindent An up-to-date list of currently supported devices can be obtained via \family typewriter sdcc -mpic14 -phelp foo.c \family default (foo.c must exist...). \end_layout \begin_layout Subsection PIC Code Pages \begin_inset Index idx status collapsed \begin_layout Plain Layout code page (pic14) \end_layout \end_inset and Memory Banks \begin_inset Index idx status collapsed \begin_layout Plain Layout Memory bank (pic14) \end_layout \end_inset \end_layout \begin_layout Standard The linker organizes allocation for the code page and RAM banks. It does not have intimate knowledge of the code flow. It will put all the code section of a single .asm file into a single code page. In order to make use of multiple code pages, separate asm files must be used. The compiler assigns all \emph on static \emph default functions of a single .c file into the same code page. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset To get the best results, follow these guidelines: \end_layout \begin_layout Enumerate Make local functions static, as non static functions require code page selection overhead. \begin_inset Newline newline \end_inset Due to the way sdcc handles functions, place called functions prior to calling functions in the file wherever possible: Otherwise sdcc will insert unnecessary pagesel directives around the call, believing that the called function is externally defined. \end_layout \begin_layout Enumerate For devices that have multiple code pages it is more efficient to use the same number of files as pages: Use up to 4 separate .c files for the 16F877, but only 2 files for the 16F874. This way the linker can put the code for each file into different code pages and there will be less page selection overhead. \end_layout \begin_layout Enumerate And as for any 8 bit micro (especially for PIC14 as they have a very simple instruction set), use `unsigned char' wherever possible instead of `int'. \end_layout \begin_layout Subsection Adding New Devices to the Port \end_layout \begin_layout Standard Adding support for a new 14 \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash , \end_layout \end_inset bit PIC MCU requires the following steps: \end_layout \begin_layout Enumerate Create a new device description. \begin_inset Newline newline \end_inset Each device is described in two files: pic16f*.h and pic16f*.c. These files primarily define SFRs, structs to access their bits, and symbolic configuration options. Both files can be generated from gputils' .inc files using the perl script \family typewriter support/scripts/inc2h.pl \family default . This file also contains further instructions on how to proceed. \end_layout \begin_layout Enumerate Copy the .h file into SDCC's include path and either add the .c file to your project or copy it to \family typewriter device/lib/pic/libdev \family default . Afterwards, rebuild and install the libraries. \end_layout \begin_layout Enumerate Edit pic14devices.txt in SDCC's include path ( \family typewriter device/include/pic/ \family default in the source tree or \family typewriter /usr/local/share/sdcc/include/pic \family default after installation). \begin_inset Newline newline \end_inset You need to add a device specification here to make the memory layout (code banks, RAM, aliased memory regions, ...) known to the compiler. Probably you can copy and modify an existing entry. The file format is documented at the top of the file. \end_layout \begin_layout Subsection Interrupt Code \end_layout \begin_layout Standard For the interrupt function, use the keyword \emph on __interrupt \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC14!interrupt \end_layout \end_inset with level number of 0 (PIC14 only has 1 interrupt so this number is only there to avoid a syntax error - it ought to be fixed). E.g.: \end_layout \begin_layout Verse \family typewriter void Intr(void) __interrupt 0 \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset T0IF = 0; /* Clear timer interrupt */ \begin_inset Newline newline \end_inset } \end_layout \begin_layout Subsection Configuration Bits \end_layout \begin_layout Standard Configuration bits (also known as fuses) can be configured using ` \family typewriter __code \family default ' and ` \family typewriter __at \family default ' modifiers. Possible options should be ANDed and can be found in your processor header file. Example for PIC16F88: \end_layout \begin_layout LyX-Code \family typewriter #include //Contains config addresses and options \begin_inset Newline newline \end_inset #include //Needed for uint16_t \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset static __code uint16_t __at (_CONFIG1) configword1 = _INTRC_IO & \begin_inset Newline newline \end_inset _CP_ALL & _WDT_OFF & [...]; \begin_inset Newline newline \end_inset static __code uint16_t __at (_CONFIG2) configword2 = [...]; \end_layout \begin_layout Standard Although data type is ignored if the address ( \family typewriter __at() \family default ) refers to a config word location, using a type large enough for the configurat ion word ( \family typewriter uint16_t \family default in this case) is recommended to prevent changes in the compiler (implicit, early range check and enforcement) from breaking the definition. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset If your processor header file doesn't contain config addresses you can declare it manually or use a literal address: \end_layout \begin_layout LyX-Code \family typewriter static __code uint16_t __at (0x2007) configword1 = _INTRC_IO & \begin_inset Newline newline \end_inset _CP_ALL & _WDT_OFF & [...]; \end_layout \begin_layout Subsection Linking and Assembling \end_layout \begin_layout Standard For assembling you can use either GPUTILS' \begin_inset Index idx status collapsed \begin_layout Plain Layout gputils (pic tools) \end_layout \end_inset gpasm.exe or MPLAB's mpasmwin.exe. GPUTILS are available from \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/projects/gputils \end_layout \end_inset . For linking you can use either GPUTILS' gplink or MPLAB's mplink.exe. If you use MPLAB and an interrupt function then the linker script file vectors section will need to be enlarged to link with mplink. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Pic device specific header and c source files are automatically generated from MPLAB include files, which are published by Microchip with a special requirement that they are only to be used with authentic Microchip devices. This reqirement prevents to publish generated header and c source files under the GPL compatible license, so they are located in non-free directory (see section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Search-Paths" \end_inset ). In order to include them in include and library search paths, the \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-non-free \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-non-free \end_layout \end_inset \series default command line option should be defined. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset NOTE: the compiled code, which use non-free pic device specific libraries, is not GPL compatible! \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Here is a \family typewriter Makefile \family default using GPUTILS: \end_layout \begin_layout Verse \family typewriter .c.o: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcc -V --use-non-free -mpic14 -p16f877 -c $< \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset $(PRJ).hex: $(OBJS) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset gplink -m -s $(PRJ).lkr -o $(PRJ).hex $(OBJS) libsdcc.lib \end_layout \begin_layout Standard Here is a \family typewriter Makefile \family default using MPLAB: \end_layout \begin_layout Verse \family typewriter .c.o: \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcc -S -V --use-non-free -mpic14 -p16f877 $< \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mpasmwin /q /o $*.asm \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset $(PRJ).hex: $(OBJS) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mplink /v $(PRJ).lkr /m $(PRJ).map /o $(PRJ).hex $(OBJS) libsdcc.lib \end_layout \begin_layout Standard Please note that indentations within a \family typewriter Makefile \family default have to be done with a tabulator character. \end_layout \begin_layout Subsection Command-Line Options \end_layout \begin_layout Standard Besides the switches common to all SDCC backends, the PIC14 port accepts the following options (for an updated list see sdcc - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -help): \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug-xtra \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC14!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug-extra \end_layout \end_inset emit debug info in assembly output \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-pcode-opt \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC14!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-pcode-opt \end_layout \end_inset disable (slightly faulty) optimization on pCode \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-loc \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC14!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-loc \end_layout \end_inset sets the lowest address of the argument passing stack (defaults to a suitably large shared databank to reduce BANKSEL overhead) \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-size \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC14!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -stack-size \end_layout \end_inset sets the size if the argument passing stack (default: 16, minimum: 4) \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-non-free \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC14!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-non-free \end_layout \end_inset make non-free device headers and libraries available in the compiler's search paths (implicit -I and -L options) \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-extended-instructions forbid use of the extended instruction set (e.g., ADDFSR) \end_layout \begin_layout Subsection Environment Variables \end_layout \begin_layout Standard The PIC14 port recognizes the following environment variables: \end_layout \begin_layout Description SDCC_PIC14_SPLIT_LOCALS \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC14!Environment variables!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset PIC14 \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset SPLIT \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset LOCALS \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Environment variables!SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset PIC14 \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset SPLIT \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset LOCALS \end_layout \end_inset If set and not empty, sdcc will allocate each temporary register (the ones called r0xNNNN) in a section of its own. By default (if this variable is unset), sdcc tries to cluster registers in sections in order to reduce the BANKSEL overhead when accessing them. \end_layout \begin_layout Subsection The Library \end_layout \begin_layout Standard The PIC14 library currently only contains support routines required by the compiler to implement multiplication, division, and floating point support. No libc-like replacement is available at the moment, though many of the common sdcc library sources (in \family typewriter device/lib \family default ) should also compile with the PIC14 port. \end_layout \begin_layout Subsubsection Enhanced cores \end_layout \begin_layout Standard SDCC/PIC14 has experimental support for devices with the enhanced 14-bit cores (such as pic12f1822). Due to differences in required code, the libraries provided with SDCC ( \family typewriter libm.lib \family default and \family typewriter libsdcc.lib \family default ) are now provided in two variants: \family typewriter libm.lib \family default and \family typewriter libsdcc.lib \family default are compiled for the regular, non-enhanced devices. \family typewriter libme.lib \family default and \family typewriter libsdcce.lib \family default (note the trailing ' \family typewriter e \family default ') are compiled for enhanced devices. When linking manually, make sure to select the proper variant! \end_layout \begin_layout Standard When SDCC is used to invoke the linker, SDCC will automatically select the \family typewriter libsdcc.lib \family default -variant suitable for the target device. However, no such magic has been conjured up for \family typewriter libm.lib \family default ! \end_layout \begin_layout Subsubsection Accessing bits of special function registers \end_layout \begin_layout Standard Individual bits within SFRs can be accessed either using \family typewriter bits. \family default or using a shorthand \family typewriter \family default , which is defined in the respective device header for all \family typewriter \family default s. In order to avoid polluting the global namespace with the names of all the bits, you can \family typewriter #define NO_BIT_DEFINES \family default before inclusion of the device header file. \end_layout \begin_layout Subsubsection Naming of special function registers \begin_inset CommandInset label LatexCommand label name "subsec:Naming-of-special" \end_inset \end_layout \begin_layout Standard If \family typewriter NO_BIT_DEFINES \family default is used, individual bits of the SFRs can be accessed as \family typewriter bits. \family default . With the 3.1.0 release, the previously used \family typewriter _bits. \family default (note the underscore) is deprecated. This was done to align the naming conventions with the PIC16 port and competing compiler vendors. To avoid polluting the global namespace with the legacy names, you can prevent their definition using \family typewriter #define NO_LEGACY_NAMES \family default prior to the inclusion of the device header. \end_layout \begin_layout Standard You \family typewriter \series bold must \family default \series default also \family typewriter #define NO_BIT_DEFINES \family default in order to access SFRs as \family typewriter bits. \family default , otherwise \family typewriter \family default will expand to \family typewriter bits. \family default , yielding the undefined expression \family typewriter bits.bits. \family default . \end_layout \begin_layout Subsubsection error: missing definition for symbol ``__gptrget1'' \end_layout \begin_layout Standard The PIC14 port uses library routines to provide more complex operations like multiplication, division/modulus and (generic) pointer dereferencing. In order to add these routines to your project, you must link with PIC14's \family typewriter libsdcc.lib \family default . For single source file projects this is done automatically, more complex projects must add \family typewriter libsdcc.lib \family default to the linker's arguments. Make sure you also add an include path for the library (using the -I switch to the linker)! \end_layout \begin_layout Subsubsection Processor mismatch in file ``XXX''. \end_layout \begin_layout Standard This warning can usually be ignored due to the very good compatibility amongst 14 \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash , \end_layout \end_inset bit PIC \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC14 \end_layout \end_inset devices. \end_layout \begin_layout Standard You might also consider recompiling the library for your specific device by changing the ARCH=p16f877 (default target) entry in \family typewriter device/lib/pic/Makefile.in \family default and \family typewriter device/lib/pic/Makefile \family default to reflect your device. This might even improve performance for smaller devices as unnecessary BANKSELs might be removed. \end_layout \begin_layout Subsection Known Bugs \end_layout \begin_layout Subsubsection Function arguments \end_layout \begin_layout Standard Functions with variable argument lists (like printf) are not yet supported. Similarly, taking the address of the first argument passed into a function does not work: It is currently passed in WREG and has no address... \end_layout \begin_layout Subsubsection Regression tests fail \end_layout \begin_layout Standard Though the small subset of regression tests in src/regression passes, SDCC regression test suite does not, indicating that there are still major bugs in the port. However, many smaller projects have successfully used SDCC in the past... \end_layout \begin_layout Section The PIC16 \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16 \end_layout \end_inset port \end_layout \begin_layout Standard The PIC16 port adds support for Microchip \begin_inset Index idx status collapsed \begin_layout Plain Layout Microchip \end_layout \end_inset \begin_inset Formula $^{\text{TM}}$ \end_inset PIC \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC \end_layout \end_inset \begin_inset Formula $^{\text{TM}}$ \end_inset MCUs with 16 bit wide instructions. This port is not yet mature and still lacks many features. However, it can work for simple code. Currently this family of microcontrollers contains the PIC18Fxxx and PIC18Fxxxx ; devices supported by the port include: \end_layout \begin_layout Standard \begin_inset VSpace defskip \end_inset \end_layout \begin_layout Standard 18F13K22 18F13K50 \end_layout \begin_layout Standard 18F14K22 18F14K50 \end_layout \begin_layout Standard 18F23K20 18F23K22 \end_layout \begin_layout Standard 18F24J10 18F24J11 18F24J50 18F24K20 18F24K22 18F24K50 \end_layout \begin_layout Standard 18F25J10 18F25J11 18F25J50 18F25K20 18F25K22 18F25K50 18F25K80 \end_layout \begin_layout Standard 18F26J11 18F26J13 18F26J50 18F26J53 18F26K20 18F26K22 18F26K80 \end_layout \begin_layout Standard 18F27J13 18F27J53 \end_layout \begin_layout Standard 18F43K20 18F43K22 \end_layout \begin_layout Standard 18F44J10 18F44J11 18F44J50 18F44K20 18F44K22 \end_layout \begin_layout Standard 18F45J10 18F45J11 18F45J50 18F45K20 18F45K22 18F45K50 18F45K80 \end_layout \begin_layout Standard 18F46J11 18F46J13 18F46J50 18F46J53 18F46K20 18F46K22 18F46K80 \end_layout \begin_layout Standard 18F47J13 18F47J53 \end_layout \begin_layout Standard 18F63J11 18F63J90 \end_layout \begin_layout Standard 18F64J11 18F64J90 \end_layout \begin_layout Standard 18F65J10 18F65J11 18F65J15 18F65J50 18F65J90 18F65J94 18F65K22 18F65K80 18F65K90 \end_layout \begin_layout Standard 18F66J10 18F66J11 18F66J15 18F66J16 18F66J50 18F66J55 18F66J60 18F66J65 \end_layout \begin_layout Standard 18F66J90 18F66J93 18F66J94 18F66J99 18F66K22 18F66K80 18F66K90 \end_layout \begin_layout Standard 18F67J10 18F67J11 18F67J50 18F67J60 18F67J90 18F67J93 18F67J94 18F67K22 18F67K90 \end_layout \begin_layout Standard 18F83J11 18F83J90 \end_layout \begin_layout Standard 18F84J11 18F84J90 \end_layout \begin_layout Standard 18F85J10 18F85J11 18F85J15 18F85J50 18F85J90 18F85J94 18F85K22 18F85K90 \end_layout \begin_layout Standard 18F86J10 18F86J11 18F86J15 18F86J16 18F86J50 18F86J55 18F86J60 18F86J65 \end_layout \begin_layout Standard 18F86J72 18F86J90 18F86J93 18F86J94 18F86J99 18F86K22 18F86K90 \end_layout \begin_layout Standard 18F87J10 18F87J11 18F87J50 18F87J60 18F87J72 18F87J90 18F87J93 18F87J94 18F87K22 18F87K90 \end_layout \begin_layout Standard 18F95J94 18F96J60 18F96J65 18F96J94 18F96J99 \end_layout \begin_layout Standard 18F97J60 18F97J94 \end_layout \begin_layout Standard 18F242 18F248 18F252 18F258 \end_layout \begin_layout Standard 18F442 18F448 18F452 18F458 \end_layout \begin_layout Standard 18F1220 18F1230 \end_layout \begin_layout Standard 18F1320 18F1330 \end_layout \begin_layout Standard 18F2220 18F2221 \end_layout \begin_layout Standard 18F2320 18F2321 18F2331 \end_layout \begin_layout Standard 18F2410 18F2420 18F2423 18F2431 18F2439 18F2450 18F2455 18F2458 18F2480 \end_layout \begin_layout Standard 18F2510 18F2515 18F2520 18F2523 18F2525 18F2539 18F2550 18F2553 18F2580 18F2585 \end_layout \begin_layout Standard 18F2610 18F2620 18F2680 18F2682 18F2685 \end_layout \begin_layout Standard 18F4220 18F4221 \end_layout \begin_layout Standard 18F4320 18F4321 18F4331 \end_layout \begin_layout Standard 18F4410 18F4420 18F4423 18F4431 18F4439 18F4450 18F4455 18F4458 18F4480 \end_layout \begin_layout Standard 18F4510 18F4515 18F4520 18F4523 18F4525 18F4539 18F4550 18F4553 18F4580 18F4585 \end_layout \begin_layout Standard 18F4610 18F4620 18F4680 18F4682 18F4685 \end_layout \begin_layout Standard 18F6310 18F6390 18F6393 \end_layout \begin_layout Standard 18F6410 18F6490 18F6493 \end_layout \begin_layout Standard 18F6520 18F6525 18F6527 18F6585 \end_layout \begin_layout Standard 18F6620 18F6621 18F6622 18F6627 18F6628 18F6680 \end_layout \begin_layout Standard 18F6720 18F6722 18F6723 \end_layout \begin_layout Standard 18F8310 18F8390 18F8393 \end_layout \begin_layout Standard 18F8410 18F8490 18F8493 \end_layout \begin_layout Standard 18F8520 18F8525 18F8527 18F8585 \end_layout \begin_layout Standard 18F8620 18F8621 18F8622 18F8627 18F8628 18F8680 \end_layout \begin_layout Standard 18F8720 18F8722 18F8723 \end_layout \begin_layout Standard 18LF13K22 18LF13K50 \end_layout \begin_layout Standard 18LF14K22 18LF14K50 \end_layout \begin_layout Standard 18LF23K22 18LF24J10 18LF24J11 18LF24J50 18LF24K22 18LF24K50 \end_layout \begin_layout Standard 18LF25J10 18LF25J11 18LF25J50 18LF25K22 18LF25K50 18LF25K80 \end_layout \begin_layout Standard 18LF26J11 18LF26J13 18LF26J50 18LF26J53 18LF26K22 18LF26K80 \end_layout \begin_layout Standard 18LF27J13 18LF27J53 \end_layout \begin_layout Standard 18LF43K22 \end_layout \begin_layout Standard 18LF44J10 18LF44J11 18LF44J50 18LF44K22 \end_layout \begin_layout Standard 18LF45J10 18LF45J11 18LF45J50 18LF45K22 18LF45K50 18LF45K80 \end_layout \begin_layout Standard 18LF46J11 18LF46J13 18LF46J50 18LF46J53 18LF46K22 18LF46K80 \end_layout \begin_layout Standard 18LF47J13 18LF47J53 \end_layout \begin_layout Standard 18LF65K80 \end_layout \begin_layout Standard 18LF66K80 \end_layout \begin_layout Standard 18LF242 18LF248 18LF252 18LF258 \end_layout \begin_layout Standard 18LF442 18LF448 18LF452 18LF458 \end_layout \begin_layout Standard 18LF1220 18LF1230 \end_layout \begin_layout Standard 18LF1320 18LF1330 \end_layout \begin_layout Standard 18LF2220 18LF2221 \end_layout \begin_layout Standard 18LF2320 18LF2321 18LF2331 \end_layout \begin_layout Standard 18LF2410 18LF2420 18LF2423 18LF2431 18LF2439 18LF2450 18LF2455 18LF2458 18LF2480 \end_layout \begin_layout Standard 18LF2510 18LF2515 18LF2520 18LF2523 18LF2525 18LF2539 18LF2550 18LF2553 18LF2580 18LF2585 \end_layout \begin_layout Standard 18LF2610 18LF2620 18LF2680 18LF2682 18LF2685 \end_layout \begin_layout Standard 18LF4220 18LF4221 \end_layout \begin_layout Standard 18LF4320 18LF4321 18LF4331 \end_layout \begin_layout Standard 18LF4410 18LF4420 18LF4423 18LF4431 18LF4439 18LF4450 18LF4455 18LF4458 18LF4480 \end_layout \begin_layout Standard 18LF4510 18LF4515 18LF4520 18LF4523 18LF4525 18LF4539 18LF4550 18LF4553 18LF4580 18LF4585 \end_layout \begin_layout Standard 18LF4610 18LF4620 18LF4680 18LF4682 18LF4685 \end_layout \begin_layout Standard 18LF6310 18LF6390 18LF6393 \end_layout \begin_layout Standard 18LF6410 18LF6490 18LF6493 \end_layout \begin_layout Standard 18LF6520 18LF6525 18LF6527 18LF6585 \end_layout \begin_layout Standard 18LF6620 18LF6621 18LF6622 18LF6627 18LF6628 18LF6680 \end_layout \begin_layout Standard 18LF6720 18LF6722 18LF6723 \end_layout \begin_layout Standard 18LF8310 18LF8390 18LF8393 \end_layout \begin_layout Standard 18LF8410 18LF8490 18LF8493 \end_layout \begin_layout Standard 18LF8520 18LF8525 18LF8527 18LF8585 \end_layout \begin_layout Standard 18LF8620 18LF8621 18LF8622 18LF8627 18LF8628 18LF8680 \end_layout \begin_layout Standard 18LF8720 18LF8722 18LF8723 \end_layout \begin_layout Standard \begin_inset VSpace defskip \end_inset \end_layout \begin_layout Standard \noindent An up-to-date list of supported devices is also available via ' \family typewriter sdcc -mpic16 -plist \family default '. \end_layout \begin_layout Subsection Global Options \end_layout \begin_layout Standard PIC16 port supports the standard command line arguments as supposed, with the exception of certain cases that will be mentioned in the following list: \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -callee-saves \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -callee-saves \end_layout \end_inset See - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -all-callee-saves \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-non-free \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!Options!- \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-non-free \end_layout \end_inset Make non-free device headers and libraries available in the compiler's search paths (implicit -I and -L options). \end_layout \begin_layout Subsection Port Specific Options \begin_inset Index idx status collapsed \begin_layout Plain Layout Options PIC16 \end_layout \end_inset \end_layout \begin_layout Standard The port specific options appear after the global options in the sdcc - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -help output. \end_layout \begin_layout Subsubsection Code Generation Options \end_layout \begin_layout Standard These options influence the generated assembler code. \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -pstack-model=[model] Used in conjunction with the command above. Defines the stack model to be used, valid stack models are: \begin_inset Separator latexpar \end_inset \end_layout \begin_deeper \begin_layout Labeling \labelwidthstring 00.00.0000 \emph on small \emph default Selects small stack model. 8 bit stack and frame pointers. Supports 256 bytes stack size. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \emph on large \emph default Selects large stack model. 16 bit stack and frame pointers. Supports 65536 bytes stack size. \end_layout \end_deeper \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -pno-banksel Do not generate BANKSEL assembler directives. \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -extended Enable extended instruction set/literal offset addressing mode. Use with care! \end_layout \begin_layout Subsubsection Optimization Options \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -obanksel=n Set optimization level for inserting BANKSELs. \begin_inset Newline newline \end_inset \begin_inset Separator latexpar \end_inset \end_layout \begin_deeper \begin_layout Labeling \labelwidthstring 00.00.0000 0 no optimization \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 1 checks previous used register and if it is the same then does not emit BANKSEL, accounts only for labels. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 2 tries to check the location of (even different) symbols and removes BANKSELs if they are in the same bank. \begin_inset Newline newline \end_inset \emph on Important: There might be problems if the linker script has data sections across bank borders! \end_layout \end_deeper \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -denable-peeps Force the usage of peepholes. Use with care. \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-optimize-goto Do not use (conditional) BRA instead of GOTO. \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -optimize-cmp Try to optimize some compares. \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -optimize-df Analyze the dataflow of the generated code and improve it. \end_layout \begin_layout Subsubsection Assembling Options \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -asm= Sets the full path and name of an external assembler to call. \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -mplab-comp MPLAB \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!MPLAB \end_layout \end_inset compatibility option. Currently only suppresses special gpasm directives. \end_layout \begin_layout Subsubsection Linking Options \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -link= Sets the full path and name of an external linker to call. \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -preplace-udata-with=[kword] Replaces the default udata keyword for allocating unitialized data variables with [kword]. Valid keywords are: "udata_acs", "udata_shr", "udata_ovr". \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -ivt-loc=n Place the interrupt vector table at address \emph on n \emph default . Useful for bootloaders. \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -nodefaultlibs Do not link default libraries when linking. \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-crt= Use a custom run-time module instead of the default (crt0i). \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -no-crt Don't link the default run-time modules \end_layout \begin_layout Subsubsection Debugging Options \end_layout \begin_layout Standard Debugging options enable extra debugging information in the output files. \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug-xtra Similar to - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug \end_layout \end_inset , but dumps more information. \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug-ralloc Force register allocator to dump .d file with debugging information. is the name of the file being compiled. \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -pcode-verbose Enable pcode debugging information in translation. \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -calltree Dump call tree in .calltree file. \end_layout \begin_layout Description - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -gstack Trace push/pops for stack pointer overflow. \end_layout \begin_layout Subsection Environment Variables \end_layout \begin_layout Standard There is a number of environmental variables that can be used when running SDCC to enable certain optimizations or force a specific program behaviour. these variables are primarily for debugging purposes so they can be enabled/dis abled at will. \end_layout \begin_layout Standard Currently there is only two such variables available: \end_layout \begin_layout Description OPTIMIZE_BITFIELD_POINTER_GET \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!Environment variables!OPTIMIZE \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset BITFIELD \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset POINTER \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset GET \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Environment variables!OPTIMIZE \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset BITFIELD \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset POINTER \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset GET (PIC16) \end_layout \end_inset When this variable exists, reading of structure bit-fields is optimized by directly loading FSR0 with the address of the bit-field structure. Normally SDCC will cast the bit-field structure to a bit-field pointer and then load FSR0. This step saves data ram and code space for functions that make heavy use of bit-fields. (i.e., 80 bytes of code space are saved when compiling malloc.c with this option). \end_layout \begin_layout Description NO_REG_OPT \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!Environment variables!NO \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset REG \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset OPT \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Environment variables!NO \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset REG \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset OPT \end_layout \end_inset Do not perform pCode registers optimization. This should be used for debugging purposes. If bugs in the pcode optimizer are found, users can benefit from temporarily disabling the optimizer until the bug is fixed. \end_layout \begin_layout Subsection Preprocessor Macros \begin_inset Index idx status collapsed \begin_layout Plain Layout Preprocessor!PIC16 Macros \end_layout \end_inset \end_layout \begin_layout Standard PIC16 \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16 \end_layout \end_inset port defines the following preprocessor macros while translating a source. \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout Macro \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_pic16 \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC!Defines!__SDCC \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset pic16 \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Port identification \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout pic18fxxxx \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!Defines!pic18fxxxx \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout MCU Identification. \emph on xxxx \emph default is the microcontrol identification number, i.e. 452, 6620, etc \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout _ \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset _18Fxxxx \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!Defines! \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset pic18fxxxx \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout MCU Identification (same as above) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout STACK_MODEL_nnn \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!Defines!STACK \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset MODEL \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset nnn \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout nnn = SMALL or LARGE respectively according to the stack model used \end_layout \end_inset \end_inset \end_layout \begin_layout Standard \noindent In addition the following macros are defined when calling assembler: \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout Macro \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __18Fxxxx \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout MCU Identification. \emph on xxxx \emph default is the microcontrol identification number, i.e. 452, 6620, etc \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout __SDCC_MODEL_nnn \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout nnn = SMALL or LARGE respectively according to the memory model used for SDCC \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout STACK_MODEL_nnn \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout nnn = SMALL or LARGE respectively according to the stack model used \end_layout \end_inset \end_inset \end_layout \begin_layout Subsection Directories \end_layout \begin_layout Standard PIC16 \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16 \end_layout \end_inset port uses the following directories for searching header files and libraries. \begin_inset Newline newline \end_inset \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout Directory \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Target \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Command prefix \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout PREFIX/sdcc/include/pic16 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout PIC16 specific headers \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Compiler \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout -I \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout PREFIX/sdcc/lib/pic16 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout PIC16 specific libraries \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Linker \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout -L \end_layout \end_inset \end_inset \end_layout \begin_layout Standard If the \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-non-free \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-non-free \end_layout \end_inset \series default command line option is specified, non-free directories are searched: \begin_inset Newline newline \end_inset \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout Directory \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Target \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Command prefix \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout PREFIX/sdcc/non-free/include/pic16 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout PIC16 specific non-free headers \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Compiler \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout -I \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout PREFIX/sdcc/non-free/lib/pic16 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout PIC16 specific non-free libraries \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Linker \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout -L \end_layout \end_inset \end_inset \end_layout \begin_layout Subsection Pragmas \begin_inset CommandInset label LatexCommand label name "subsec:PIC16_Pragmas" \end_inset \end_layout \begin_layout Standard The PIC16 \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16 \end_layout \end_inset port currently supports the following pragmas: \end_layout \begin_layout Description stack \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!Pragmas! \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma stack \end_layout \end_inset This forces the code generator to initialize the stack & frame pointers at a specific address. This is an ad hoc solution for cases where no STACK directive is available in the linker script or gplink is not instructed to create a stack section. \begin_inset Newline newline \end_inset The stack pragma should be used only once in a project. Multiple pragmas may result in indeterminate behaviour of the program. \begin_inset Foot status collapsed \begin_layout Plain Layout The old format (ie. #pragma stack 0x5ff) is deprecated and will cause the stack pointer to cross page boundaries (or even exceed the available data RAM) and crash the program. Make sure that stack does not cross page boundaries when using the SMALL stack model. \end_layout \end_inset \begin_inset Newline newline \end_inset The format is as follows: \end_layout \begin_layout LyX-Code #pragma stack bottom_address [stack_size] \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard \emph on bottom_address \emph default is the lower bound of the stack section. The stack pointer initially will point at address (bottom_address+stack_size-1). \end_layout \begin_layout LyX-Code Example: \end_layout \begin_layout LyX-Code \end_layout \begin_layout LyX-Code /* initializes stack of 100 bytes at RAM address 0x200 */ \end_layout \begin_layout LyX-Code #pragma stack 0x200 100 \end_layout \begin_layout Standard If the stack_size field is omitted then a stack is created with the default size of 64. This size might be enough for most programs, but its not enough for operations with deep function nesting or excessive stack usage. \end_layout \begin_layout Description code \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!Pragmas! \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma code \end_layout \end_inset Force a function to a static FLASH address. \end_layout \begin_layout LyX-Code Example: \end_layout \begin_layout LyX-Code \end_layout \begin_layout LyX-Code /* place function test_func at 0x4000 */ \end_layout \begin_layout LyX-Code #pragma code test_func 0x4000 \end_layout \begin_layout LyX-Code \end_layout \begin_layout Description library \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!Pragmas! \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma library \end_layout \end_inset instructs the linker to use a library module. \begin_inset Newline newline \end_inset Usage: \end_layout \begin_layout LyX-Code #pragma library module_name \end_layout \begin_layout Standard \emph on module_name \emph default can be any library or object file (including its path). Note that there are four reserved keywords which have special meaning. These are: \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout Keyword \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Module to link \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold ignore \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout ignore all library pragmas \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on (none) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout link the C library \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on libc18f \emph default .lib \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold math \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout link the Math libarary \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on libm18f \emph default .lib \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold io \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout link the I/O library \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on libio18f* \emph default .lib \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold debug \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout link the debug library \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \emph on libdebug \emph default .lib \end_layout \end_inset \end_inset \begin_inset Newline newline \end_inset * is the device number, i.e. 452 for PIC18F452 MCU. \end_layout \begin_layout Standard \noindent This feature allows for linking with specific libraries without having to explicit name them in the command line. Note that the \noun on ignore \noun default keyword will reject all modules specified by the library pragma. \end_layout \begin_layout Description udata \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!Pragmas! \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma udata \end_layout \end_inset The pragma udata instructs the compiler to emit code so that linker will place a variable at a specific memory bank. \end_layout \begin_layout LyX-Code Example: \end_layout \begin_layout LyX-Code \end_layout \begin_layout LyX-Code /* places variable foo at bank2 */ \end_layout \begin_layout LyX-Code #pragma udata bank2 foo \end_layout \begin_layout LyX-Code char foo; \end_layout \begin_layout Standard In order for this pragma to work extra SECTION directives should be added in the .lkr script. In the following example a sample .lkr file is shown: \end_layout \begin_layout LyX-Code \end_layout \begin_layout LyX-Code // Sample linker script for the PIC18F452 processor \end_layout \begin_layout LyX-Code LIBPATH . \end_layout \begin_layout LyX-Code CODEPAGE NAME=vectors START=0x0 END=0x29 PROTECTED \end_layout \begin_layout LyX-Code CODEPAGE NAME=page START=0x2A END=0x7FFF \end_layout \begin_layout LyX-Code CODEPAGE NAME=idlocs START=0x200000 END=0x200007 PROTECTED \end_layout \begin_layout LyX-Code CODEPAGE NAME=config START=0x300000 END=0x30000D PROTECTED \end_layout \begin_layout LyX-Code CODEPAGE NAME=devid START=0x3FFFFE END=0x3FFFFF PROTECTED \end_layout \begin_layout LyX-Code CODEPAGE NAME=eedata START=0xF00000 END=0xF000FF PROTECTED \end_layout \begin_layout LyX-Code ACCESSBANK NAME=accessram START=0x0 END=0x7F \end_layout \begin_layout LyX-Code \end_layout \begin_layout LyX-Code DATABANK NAME=gpr0 START=0x80 END=0xFF \end_layout \begin_layout LyX-Code DATABANK NAME=gpr1 START=0x100 END=0x1FF \end_layout \begin_layout LyX-Code DATABANK NAME=gpr2 START=0x200 END=0x2FF \end_layout \begin_layout LyX-Code DATABANK NAME=gpr3 START=0x300 END=0x3FF \end_layout \begin_layout LyX-Code DATABANK NAME=gpr4 START=0x400 END=0x4FF \end_layout \begin_layout LyX-Code DATABANK NAME=gpr5 START=0x500 END=0x5FF \end_layout \begin_layout LyX-Code ACCESSBANK NAME=accesssfr START=0xF80 END=0xFFF PROTECTED \end_layout \begin_layout LyX-Code \end_layout \begin_layout LyX-Code SECTION NAME=CONFIG ROM=config \end_layout \begin_layout LyX-Code \end_layout \begin_layout LyX-Code SECTION NAME=bank0 RAM=gpr0 # these SECTION directives \end_layout \begin_layout LyX-Code SECTION NAME=bank1 RAM=gpr1 # should be added to link \end_layout \begin_layout LyX-Code SECTION NAME=bank2 RAM=gpr2 # section name 'bank?' with \end_layout \begin_layout LyX-Code SECTION NAME=bank3 RAM=gpr3 # a specific DATABANK name \end_layout \begin_layout LyX-Code SECTION NAME=bank4 RAM=gpr4 \end_layout \begin_layout LyX-Code SECTION NAME=bank5 RAM=gpr5 \end_layout \begin_layout Standard The linker will recognise the section name set in the pragma statement and will position the variable at the memory bank set with the RAM field at the SECTION line in the linker script file. \end_layout \begin_layout Description config \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!Pragmas! \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma config \end_layout \end_inset The pragma config instructs the compiler to emit config directive. \begin_inset Newline newline \end_inset The format is as follows: \end_layout \begin_layout LyX-Code #pragma config setting=value [, setting=value] \end_layout \begin_layout LyX-Code \end_layout \begin_layout Standard Multiple settings may be defined on a single line, separated by commas. Settings for a single configuration byte may also be defined on separate lines. \end_layout \begin_layout LyX-Code Example: \end_layout \begin_layout LyX-Code \end_layout \begin_layout LyX-Code #pragma config CP0=OFF,OSCS=ON,OSC=LP,BOR=ON,BORV=25,WDT=ON,WDTPS=128,CCP2MUX=ON \end_layout \begin_layout LyX-Code #pragma config STVR=ON \end_layout \begin_layout Subsection Header Files and Libraries \begin_inset CommandInset label LatexCommand label name "subsec:PIC16_Header-Files-and-Libraries" \end_inset \end_layout \begin_layout Standard Pic device specific header and c source files are automatically generated from MPLAB include files, which are published by Microchip with a special requirement that they are only to be used with authentic Microchip devices. This requirement prevents to publish generated header and c source files under the GPL compatible license, so they are located in the non-free directory (see section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Search-Paths" \end_inset ). In order to include them in include and library search paths, the \series bold - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-non-free \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -use-non-free \end_layout \end_inset \series default command line option should be defined. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset NOTE: the compiled code, which use non-free pic device specific libraries, is not GPL compatible! \end_layout \begin_layout Subsection Header Files \begin_inset CommandInset label LatexCommand label name "subsec:PIC16_Header-Files" \end_inset \end_layout \begin_layout Standard There is one main header file \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!Header files \end_layout \end_inset that can be included to the source files using the pic16 \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16 \end_layout \end_inset port. That file is the \series bold pic18fregs.h \series default . This header file contains the definitions for the processor special registers, so it is necessary if the source accesses them. It can be included by adding the following line in the beginning of the file: \end_layout \begin_layout LyX-Code #include \end_layout \begin_layout Standard The specific microcontroller is selected within the pic18fregs.h automatically, so the same source can be used with a variety of devices. \end_layout \begin_layout Subsection Libraries \begin_inset CommandInset label LatexCommand label name "subsec:pic16Libraries" \end_inset \end_layout \begin_layout Standard The libraries \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!Libraries \end_layout \end_inset that PIC16 \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16 \end_layout \end_inset port depends on are the microcontroller device libraries which contain the symbol definitions for the microcontroller special function registers. These libraries have the format pic18fxxxx.lib, where \emph on xxxx \emph default is the microcontroller identification number. The specific library is selected automatically by the compiler at link stage according to the selected device. \end_layout \begin_layout Standard \noindent Libraries are created with gplib which is part of the gputils package \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/projects/gputils \end_layout \end_inset . \end_layout \begin_layout Subsubsection* Building the libraries \end_layout \begin_layout Standard Before using SDCC/pic16 there are some libraries that need to be compiled. This process is done automatically if gputils are found at SDCC's compile time. Should you require to rebuild the pic16 libraries manually (e.g. in order to enable output of float values \begin_inset Index idx status collapsed \begin_layout Plain Layout printf()!PIC16 Floating point support \end_layout \end_inset via \family typewriter printf() \family default , see below), these are the steps required to do so under Linux or Mac OS X (cygwin might work as well, but is untested): \end_layout \begin_layout LyX-Code cd device/lib/pic16 \end_layout \begin_layout LyX-Code ./configure.gnu \end_layout \begin_layout LyX-Code cd .. \end_layout \begin_layout LyX-Code make model-pic16 \end_layout \begin_layout LyX-Code su -c 'make install' # install the libraries, you need the root password \end_layout \begin_layout LyX-Code cd ../.. \end_layout \begin_layout Standard If you need to install the headers too, do: \end_layout \begin_layout LyX-Code cd device/include \end_layout \begin_layout LyX-Code su -c 'make install' # install the headers, you need the root password \end_layout \begin_layout Subsubsection* Output of float values via printf() \end_layout \begin_layout Standard The library is normally built without support for displaying float values, only \begin_inset Index idx status collapsed \begin_layout Plain Layout \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout printf()!PIC16 floating point support \end_layout \end_inset will appear instead of the value. To change this, rebuild the library as stated above, but call \family typewriter ./configure.gnu --enable-floats \family default instead of just \family typewriter ./configure.gnu \family default . Also make sure that at least \family typewriter libc/stdio/vfprintf.c \family default is actually recompiled, e.g. by \family typewriter touch \family default ing it after the \family typewriter configure \family default run or deleting its \family typewriter .o \family default file. \end_layout \begin_layout Standard The more common approach of compiling \family typewriter vfprintf.c \family default manually with \family typewriter -DUSE_FLOATS=1 \family default should also work, but is untested. \end_layout \begin_layout Subsection Adding New Devices to the Port \end_layout \begin_layout Standard Adding support for a new 16 \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash , \end_layout \end_inset bit PIC MCU requires the following steps: \end_layout \begin_layout Enumerate Create picDEVICE.c and picDEVICE.h from pDEVICE.inc using \begin_inset Newline newline \end_inset \family typewriter perl /path/to/sdcc/support/scripts/inc2h-pic16.pl \backslash \begin_inset Newline newline \end_inset /path/to/gputils/header/pDEVICE.inc \end_layout \begin_layout Enumerate \family typewriter mv picDEVICE.h /path/to/sdcc/device/non-free/include/pic16 \end_layout \begin_layout Enumerate \family typewriter mv picDEVICE.c /path/to/sdcc/device/non-free/lib/pic16/libdev \end_layout \begin_layout Enumerate Either \begin_inset Separator latexpar \end_inset \end_layout \begin_deeper \begin_layout Enumerate add the new device to \family typewriter /path/to/sdcc/device/lib/pic16/libio/*.ignore \family default to suppress building any of the I/O libraries for the new device \begin_inset Foot status collapsed \begin_layout Plain Layout In fact, the \family typewriter .ignore \family default files are only used when auto-generating \family typewriter Makefile.am \family default using the \family typewriter .../libio/mkmk.sh \family default script. \end_layout \end_inset , or \end_layout \begin_layout Enumerate add the device (family) to \family typewriter /path/to/sdcc/support/scripts/pic18fam-h-gen.pl \family default to assign I/O styles, run the \family typewriter pic18fam-h-gen.pl \family default script to generate \family typewriter pic18fam.h.gen \family default , replace your existing \family typewriter pic18fam.h \family default with the generated file, and (if required) implement new I/O styles in \family typewriter /path/to/sdcc/device/include/pic16/{adc,i2c,usart}.h \family default and \family typewriter /path/to/sdcc/device/lib/pic16/libio/*/*. \end_layout \end_deeper \begin_layout Enumerate Edit \family typewriter /path/to/sdcc/device/include/pic16/pic18fregs.h \family default \begin_inset Newline newline \end_inset The file format is self-explanatory, just add \begin_inset Newline newline \end_inset \family typewriter #elif defined(picDEVICE) \begin_inset Newline newline \end_inset # \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash \backslash \end_layout \end_inset include \family default \begin_inset Newline newline \end_inset at the right place (keep the file sorted, please). \end_layout \begin_layout Enumerate Edit \family typewriter /path/to/sdcc/device/include/pic16devices.txt \begin_inset Newline newline \end_inset \family default Copy and modify an existing entry or create a new one and insert it at the correct place (keep the file sorted, please). \end_layout \begin_layout Enumerate \family typewriter ( cd /path/to/sdcc/device/non-free/lib/pic16 && sh update.sh ) \end_layout \begin_layout Enumerate Recompile the pic16 libraries as described in \begin_inset CommandInset ref LatexCommand ref reference "subsec:pic16Libraries" \end_inset or just configure and build sdcc again from scratch (recommended). \end_layout \begin_layout Subsection Memory Models \end_layout \begin_layout Standard The following memory models are supported by the PIC16 port: \end_layout \begin_layout Itemize small model \end_layout \begin_layout Itemize large model \end_layout \begin_layout Standard Memory model affects the default size of pointers within the source. The sizes are shown in the next table: \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout Pointer sizes according to memory model \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout small model \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout large model \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout code pointers \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 16-bits \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 24-bits \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout data pointers \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 16-bits \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 16-bits \end_layout \end_inset \end_inset \end_layout \begin_layout Standard It is advisable that all sources within a project are compiled with the same memory model. If one wants to override the default memory model, this can be done by declaring a pointer as \series bold far \series default or \series bold near \series default . Far selects large memory model's pointers, while near selects small memory model's pointers. \end_layout \begin_layout Standard The standard device libraries (see \begin_inset CommandInset ref LatexCommand ref reference "subsec:PIC16_Header-Files" \end_inset ) contain no reference to pointers, so they can be used with both memory models. \end_layout \begin_layout Subsection Stack \end_layout \begin_layout Standard The stack \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!stack \end_layout \end_inset implementation for the PIC16 port uses two indirect registers, FSR1 and FSR2. \end_layout \begin_layout Description FSR1 is assigned as stack pointer \end_layout \begin_layout Description FSR2 is assigned as frame pointer \end_layout \begin_layout Standard The following stack models are supported by the PIC16 port \end_layout \begin_layout Itemize \noun on small \noun default model \end_layout \begin_layout Itemize \noun on large \noun default model \end_layout \begin_layout Standard \noun on Small \noun default model means that only the FSRxL byte is used to access stack and frame, while \emph on \noun on large \emph default \noun default uses both FSRxL and FSRxH registers. The following table shows the stack/frame pointers sizes according to stack model and the maximum space they can address: \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout Stack & Frame pointer sizes according to stack model \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout small \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout large \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Stack pointer FSR1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 8-bits \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 16-bits \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Frame pointer FSR2 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 8-bits \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 16-bits \end_layout \end_inset \end_inset \end_layout \begin_layout Standard \noindent \noun on Large \noun default stack model is currently not working properly throughout the code generator. So its use is not advised. Also there are some other points that need special care: \end_layout \begin_layout Enumerate Do not create stack sections with size more than one physical bank (that is 256 bytes) \end_layout \begin_layout Enumerate Stack sections should no cross physical bank limits (i.e. #pragma stack 0x50 0x100) \end_layout \begin_layout Standard These limitations are caused by the fact that only FSRxL is modified when using SMALL stack model, so no more than 256 bytes of stack can be used. This problem will disappear after LARGE model is fully implemented. \end_layout \begin_layout Subsection Functions \end_layout \begin_layout Standard In addition to the standard SDCC function keywords, PIC16 \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16 \end_layout \end_inset port makes available two more: \end_layout \begin_layout Description __wparam \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!wparam \end_layout \end_inset Use the WREG to pass one byte of the first function argument. This improves speed but you may not use this for functions with arguments that are called via function pointers, otherwise the first byte of the first parameter will get lost. Usage: \end_layout \begin_layout LyX-Code void func_wparam(int a) __wparam \end_layout \begin_layout LyX-Code { \end_layout \begin_layout LyX-Code /* WREG hold the lower part of a */ \end_layout \begin_layout LyX-Code /* the high part of a is stored in FSR2+2 (or +3 for large stack model) */ \end_layout \begin_layout LyX-Code ... \end_layout \begin_layout LyX-Code } \end_layout \begin_layout Description __shadowregs \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!shadowregs \end_layout \end_inset When entering/exiting an ISR, it is possible to take advantage of the PIC18F hardware shadow registers which hold the values of WREG, STATUS and BSR registers. This can be done by adding the keyword \emph on __shadowregs \emph default before the \emph on __interrupt \emph default keyword in the function's header. \end_layout \begin_layout LyX-Code void isr_shadow(void) __shadowregs __interrupt 1 \end_layout \begin_layout LyX-Code { \end_layout \begin_layout LyX-Code ... \end_layout \begin_layout LyX-Code } \end_layout \begin_layout Standard \emph on __shadowregs \emph default instructs the code generator not to store/restore WREG, STATUS, BSR when entering/exiting the ISR. \end_layout \begin_layout Subsection Function return values \end_layout \begin_layout Standard Return values from functions are placed to the appropriate registers following a modified Microchip policy optimized for SDCC. The following table shows these registers: \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout size \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout destination register \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 8 bits \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout WREG \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 16 bits \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout PRODL:WREG \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 24 bits \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout PRODH:PRODL:WREG \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 32 bits \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout FSR0L:PRODH:PRODL:WREG \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout >32 bits \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout on stack, FSR0 points to the beginning \end_layout \end_inset \end_inset \end_layout \begin_layout Subsection Interrupts \end_layout \begin_layout Standard An interrupt \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!interrupt \end_layout \end_inset service routine (ISR) is declared using the \emph on __interrupt \emph default keyword. \end_layout \begin_layout LyX-Code void isr(void) __interrupt \emph on n \end_layout \begin_layout LyX-Code { \end_layout \begin_layout LyX-Code ... \end_layout \begin_layout LyX-Code } \end_layout \begin_layout Standard \emph on n \emph default is the interrupt number, which for PIC18F devices can be: \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout \emph on n \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Interrupt Vector \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Interrupt Vector Address \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout RESET vector \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0x000000 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none 1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none HIGH priority interrupts \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0x000008 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 2 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout LOW priority interrupts \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0x000018 \end_layout \end_inset \end_inset \end_layout \begin_layout Standard When generating assembly code for ISR the code generator places a \noun on goto \noun default instruction at the \emph on Interrupt Vector Address \emph default which points at the generated ISR. This single GOTO instruction is part of an automatically generated \emph on interrupt entry point \emph default function. The actual ISR code is placed as normally would in the code space. Upon interrupt request, the GOTO instruction is executed which jumps to the ISR code. When declaring interrupt functions as _naked this GOTO instruction is \series bold not \series default generated. The whole interrupt functions is therefore placed at the Interrupt Vector Address of the specific interrupt. This is not a problem for the LOW priority interrupts, but it is a problem for the RESET and the HIGH priority interrupts because code may be written at the next interrupt's vector address and cause indeterminate program behaviour if that interrupt is raised. \begin_inset Foot status collapsed \begin_layout Plain Layout This is not a problem when \end_layout \begin_layout Enumerate this is a HIGH interrupt ISR and LOW interrupts are \emph on disabled \emph default or not used. \end_layout \begin_layout Enumerate when the ISR is small enough not to reach the next interrupt's vector address. \end_layout \end_inset \end_layout \begin_layout Standard \emph on n \emph default may be omitted. This way a function is generated similar to an ISR, but it is not assigned to any interrupt. \end_layout \begin_layout Standard When entering an interrupt, currently the PIC16 \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16 \end_layout \end_inset port automatically saves the following registers: \end_layout \begin_layout Itemize WREG \end_layout \begin_layout Itemize STATUS \end_layout \begin_layout Itemize BSR \end_layout \begin_layout Itemize PROD (PRODL and PRODH) \end_layout \begin_layout Itemize FSR0 (FSR0L and FSR0H) \end_layout \begin_layout Standard These registers are restored upon return from the interrupt routine. \begin_inset Foot status collapsed \begin_layout Plain Layout NOTE that when the _naked attribute is specified for an interrupt routine, then NO registers are stored or restored. \end_layout \end_inset \end_layout \begin_layout Subsection Generic Pointers \end_layout \begin_layout Standard Generic pointers are implemented in PIC16 port as 3-byte (24-bit) types. There are 3 types of generic pointers currently implemented data, code and eeprom pointers. They are differentiated by the value of the 7th and 6th bits of the upper byte: \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout pointer type \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 7th bit \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 6th bit \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout rest of the pointer \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout data \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family typewriter \shape slanted \emph on uuuuuu uuuuxxxx xxxxxxxx \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout a 12-bit data pointer in data RAM memory \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout code \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family typewriter \shape slanted \emph on uxxxxx xxxxxxxx xxxxxxxx \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout a 21-bit code pointer in FLASH memory \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout eeprom \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family typewriter \shape slanted \emph on uuuuuu uuuuuuxx xxxxxxxx \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout a 10-bit eeprom pointer in EEPROM memory \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout (unimplemented) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family typewriter \shape slanted \emph on xxxxxx xxxxxxxx xxxxxxxx \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout unimplemented pointer type \end_layout \end_inset \end_inset \end_layout \begin_layout Standard \noindent Generic pointer are read and written with a set of library functions which read/write 1, 2, 3, 4 bytes. \end_layout \begin_layout Subsection Configuration Bits \end_layout \begin_layout Standard Configuration bits (also known as fuses) can be configured using one of two methods: \end_layout \begin_layout Itemize using #pragma config (see section \begin_inset CommandInset ref LatexCommand ref reference "subsec:PIC16_Pragmas" \end_inset ), which is a preferred method for the new code. Example: \end_layout \begin_layout LyX-Code #pragma config CP0=OFF,OSCS=ON,OSC=LP,BOR=ON,BORV=25,WDT=ON,WDTPS=128,CCP2MUX=ON \end_layout \begin_layout LyX-Code #pragma config STVR=ON \end_layout \begin_layout Itemize using ` \family typewriter __code \family default ' and ` \family typewriter __at \family default ' modifiers. This method is deprecated. Possible options should be ANDed and can be found in your processor header file. Example for PIC18F2550: \end_layout \begin_layout LyX-Code \family typewriter #include //Contains config addresses and options \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset static __code char __at(__CONFIG1L) configword1l = \begin_inset Newline newline \end_inset _USBPLL_CLOCK_SRC_FROM_96MHZ_PLL_2_1L & \end_layout \begin_layout LyX-Code \family typewriter _PLLDIV_NO_DIVIDE__4MHZ_INPUT__1L & [...]; \begin_inset Newline newline \end_inset static __code char __at(__CONFIG1H) configword1h = [...]; \begin_inset Newline newline \end_inset static __code char __at(__CONFIG2L) configword2l = [...]; \begin_inset Newline newline \end_inset //More configuration words \end_layout \begin_layout Standard Mixing both methods is not allowed and throws an error message \begin_inset Quotes sld \end_inset mixing __CONFIG and CONFIG directives \begin_inset Quotes srd \end_inset . \end_layout \begin_layout Subsection PIC16 C Libraries \end_layout \begin_layout Subsubsection Standard I/O Streams \end_layout \begin_layout Standard In the \emph on stdio.h \emph default the type FILE is defined as: \end_layout \begin_layout LyX-Code typedef char * FILE; \end_layout \begin_layout Standard This type is the stream type implemented I/O in the PIC18F devices. Also the standard input and output streams are declared in stdio.h: \end_layout \begin_layout LyX-Code extern FILE * stdin; \end_layout \begin_layout LyX-Code extern FILE * stdout; \end_layout \begin_layout Standard The FILE type is actually a generic pointer which defines one more type of generic pointers, the \emph on stream \emph default pointer. This new type has the format: \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \noindent \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout pointer type \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout <7:6> \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout <5> \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout <4> \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout <3:0> \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout rest of the pointer \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout descrption \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout stream \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 00 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout 0 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout nnnn \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family typewriter \shape slanted \emph on uuuuuuuu uuuuuuuu \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout upper byte high nubble is 0x2n, the rest are zeroes \end_layout \end_inset \end_inset \end_layout \begin_layout Standard \noindent Currently implemented there are 3 types of streams defined: \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \noindent \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout stream type \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout value \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout module \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout STREAM_USART \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family typewriter 0x200000UL \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout USART \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Writes/Reads characters via the USART peripheral \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout STREAM_MSSP \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family typewriter 0x210000UL \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout MSSP \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Writes/Reads characters via the MSSP peripheral \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout STREAM_USER \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family typewriter 0x2f0000UL \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout (none) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Writes/Reads characters via used defined functions \end_layout \end_inset \end_inset \end_layout \begin_layout Standard \noindent The stream identifiers are declared as macros in the stdio.h header. \end_layout \begin_layout Standard \noindent In the libc library there exist the functions that are used to write to each of the above streams. These are \end_layout \begin_layout Description _ \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset _stream_usart_putchar writes a character at the USART stream \end_layout \begin_layout Description _ \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset _stream_mssp_putchar writes a character at the MSSP stream \end_layout \begin_layout Description putchar dummy function. This writes a character to a user specified manner. \end_layout \begin_layout Standard In order to increase performance \emph on putchar \emph default is declared in stdio.h as having its parameter in WREG (it has the \emph on __wparam \emph default keyword). In stdio.h exists the macro PUTCHAR(arg) that defines the putchar function in a user-friendly way. \emph on arg \emph default is the name of the variable that holds the character to print. An example follows: \end_layout \begin_layout LyX-Code #include \begin_inset Newline newline \end_inset #include \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset PUTCHAR( c ) \end_layout \begin_layout LyX-Code { \end_layout \begin_layout LyX-Code PORTA = c; /* dump character c to PORTA */ \end_layout \begin_layout LyX-Code } \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset void main(void) \end_layout \begin_layout LyX-Code { \end_layout \begin_layout LyX-Code stdout = STREAM_USER; /* this is not necessary, since stdout points \end_layout \begin_layout LyX-Code * by default to STREAM_USER */ \end_layout \begin_layout LyX-Code printf ( \begin_inset Quotes sld \end_inset This is a printf test \backslash n \begin_inset Quotes srd \end_inset ); \end_layout \begin_layout LyX-Code } \end_layout \begin_layout LyX-Code \end_layout \begin_layout Subsubsection Printing functions \end_layout \begin_layout Standard PIC16 contains an implementation of the printf-family \begin_inset Index idx status collapsed \begin_layout Plain Layout printf()!PIC16 \end_layout \end_inset of functions. There exist the following functions: \end_layout \begin_layout LyX-Code extern unsigned int sprintf(char *buf, char *fmt, ...); \end_layout \begin_layout LyX-Code extern unsigned int vsprintf(char *buf, char *fmt, va_list ap); \end_layout \begin_layout LyX-Code \end_layout \begin_layout LyX-Code extern unsigned int printf(char *fmt, ...); \end_layout \begin_layout LyX-Code extern unsigned int vprintf(char *fmt, va_lista ap); \end_layout \begin_layout LyX-Code \end_layout \begin_layout LyX-Code extern unsigned int fprintf(FILE *fp, char *fmt, ...); \end_layout \begin_layout LyX-Code extern unsigned int vfprintf(FILE *fp, char *fmt, va_list ap); \end_layout \begin_layout Standard For sprintf and vsprintf \emph on buf \emph default should normally be a data pointer where the resulting string will be placed. No range checking is done so the user should allocate the necessary buffer. For fprintf and vfprintf \emph on fp \emph default should be a stream pointer (i.e. stdout, STREAM_MSSP, etc...). \end_layout \begin_layout Subsubsection Signals \end_layout \begin_layout Standard The PIC18F family of microcontrollers supports a number of interrupt sources. A list of these interrupts is shown in the following table: \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align center \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout signal name \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout signal name \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_RB \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout PORTB change interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_EE \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout EEPROM/FLASH write complete interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_INT0 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout INT0 external interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_BCOL \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Bus collision interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_INT1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout INT1 external interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_LVD \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Low voltage detect interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_INT2 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout INT2 external interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_PSP \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Parallel slave port interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_CCP1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout CCP1 module interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_AD \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout AD convertion complete interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_CCP2 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout CCP2 module interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_RC \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout USART receive interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_TMR0 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout TMR0 overflow interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_TX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout USART transmit interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_TMR1 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout TMR1 overflow interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_MSSP \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SSP receive/transmit interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_TMR2 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout TMR2 matches PR2 interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout SIG_TMR3 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout TMR3 overflow interrupt \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \end_inset \end_layout \begin_layout Standard \noindent The prototypes for these names are defined in the header file \emph on signal.h \emph default . \end_layout \begin_layout Standard \noindent In order to simplify signal handling, a number of macros is provided: \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 DEF_INTHIGH(name) begin the definition of the interrupt dispatch table for high priority interrupts. \emph on name \emph default is the function name to use. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 DEF_INTLOW(name) begin the definition of the interrupt dispatch table for low priority interrupt. \emph on name \emph default is the function name to use. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 DEF_HANDLER(sig,handler) define a handler for signal \emph on sig. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 END_DEF end the declaration of the dispatch table. \end_layout \begin_layout Standard Additionally there are two more macros to simplify the declaration of the signal handler: \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 \series medium SIGHANDLER(handler) \series default this declares the function prototype for the \emph on handler \emph default function. \end_layout \begin_layout Labeling \labelwidthstring 00.00.0000 SIGHANDLERNAKED(handler) same as SIGHANDLER() but declares a naked function. \end_layout \begin_layout Standard An example of using the macros above is shown below: \end_layout \begin_layout LyX-Code #include \end_layout \begin_layout LyX-Code #include \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset DEF_INTHIGH(high_int) \end_layout \begin_layout LyX-Code DEF_HANDLER(SIG_TMR0, _tmr0_handler) \end_layout \begin_layout LyX-Code DEF_HANDLER(SIG_BCOL, _bcol_handler) \end_layout \begin_layout LyX-Code END_DEF \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset SIGHANDLER(_tmr0_handler) \end_layout \begin_layout LyX-Code { \end_layout \begin_layout LyX-Code /* action to be taken when timer 0 overflows */ \end_layout \begin_layout LyX-Code } \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset SIGHANDLERNAKED(_bcol_handler) \end_layout \begin_layout LyX-Code { \end_layout \begin_layout LyX-Code __asm \end_layout \begin_layout LyX-Code /* action to be taken when bus collision occurs */ \end_layout \begin_layout LyX-Code retfie \end_layout \begin_layout LyX-Code __endasm; \end_layout \begin_layout LyX-Code } \end_layout \begin_layout Standard \series bold NOTES: \series default Special care should be taken when using the above scheme: \end_layout \begin_layout Itemize do not place a colon (;) at the end of the DEF_* and END_DEF macros. \end_layout \begin_layout Itemize when declaring SIGHANDLERNAKED handler never forget to use \emph on retfie \emph default for proper returning. \end_layout \begin_layout Subsection PIC16 Port – Tips \end_layout \begin_layout Standard Here you can find some general tips for compiling programs with SDCC/pic16. \end_layout \begin_layout Subsubsection Stack size \end_layout \begin_layout Standard The default stack \begin_inset Index idx status collapsed \begin_layout Plain Layout PIC16!stack \end_layout \end_inset size (that is 64 bytes) probably is enough for many programs. One must take care that when there are many levels of function nesting, or there is excessive usage of stack, its size should be extended. An example of such a case is the printf/sprintf family of functions. If you encounter problems like not being able to print integers, then you need to set the stack size around the maximum (256 for small stack model). The following diagram shows what happens when calling printf to print an integer: \end_layout \begin_layout LyX-Code printf () --> ltoa () --> ultoa () --> divschar () \end_layout \begin_layout Standard It is should be understood that stack is easily consumed when calling complicate d functions. Using command line arguments like - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -fomit-frame-pointer might reduce stack usage by not creating unnecessary stack frames. Other ways to reduce stack usage may exist. \end_layout \begin_layout Subsection Known Bugs \end_layout \begin_layout Subsubsection Extended Instruction Set \end_layout \begin_layout Standard The PIC16 port emits code which is incompatible with the extended instruction set available with many newer devices. Make sure to always explicitly disable it, usually using: \end_layout \begin_layout Itemize \family typewriter #pragma config XINST=OFF \end_layout \begin_layout Standard or deprecated: \end_layout \begin_layout Itemize \family typewriter static __code char __at(__CONFIG4L) conf4l = /* more flags & */ _XINST_OFF_4L; \end_layout \begin_layout Standard \noindent Some devices (namely 18f2455, 18f2550, 18f4455, and 18f4550) use _ENHCPU_OFF_4L instead of _XINST_OFF_4L. \end_layout \begin_layout Subsubsection Regression Tests \end_layout \begin_layout Standard The PIC16 port currently passes most but not all of the tests in SDCC's regression test \begin_inset Index idx status collapsed \begin_layout Plain Layout Regression test (PIC16) \end_layout \end_inset suite (see section \begin_inset CommandInset ref LatexCommand ref reference "sec:Quality-control" \end_inset ), thus no automatic regression tests are currently performed for the PIC16 target. \end_layout \begin_layout Chapter Debugging \end_layout \begin_layout Standard There are several approaches to debugging your code. This chapter is meant to show your options and to give detail on some of them: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset When writing your code: \end_layout \begin_layout Itemize write your code with debugging in mind (avoid duplicating code, put conceptually similar variables into structs, use structured code, have strategic points within your code where all variables are consistent, ...) \end_layout \begin_layout Itemize run a syntax-checking tool like splint \begin_inset Index idx status collapsed \begin_layout Plain Layout splint (syntax checking tool) \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout lint (syntax checking tool) \end_layout \end_inset (see - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -more-pedantic \begin_inset CommandInset ref LatexCommand ref reference "lyx:more-pedantic-SPLINT" \end_inset ) over the code. \end_layout \begin_layout Itemize for the high level code use a C-compiler (like f.e. GCC) to compile run and debug the code on your host. See (see - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -more-pedantic \begin_inset CommandInset ref LatexCommand ref reference "lyx:more-pedantic-SPLINT" \end_inset ) on how to handle syntax extensions like __xdata, __at(), ... \end_layout \begin_layout Itemize use another C-compiler to compile code for your target. Always an option but not recommended:) And not very likely to help you. If you seriously consider walking this path you should at least occasionally check portability of your code. Most commercial compiler vendors will offer an evaluation version so you can test compile your code or snippets of your code. \end_layout \begin_layout Standard Debugging on a simulator: \end_layout \begin_layout Itemize there is a separate section about SDCDB (section \begin_inset CommandInset ref LatexCommand ref reference "cha:Debugging-with-SDCDB" \end_inset ) below. \end_layout \begin_layout Itemize or (8051 specific) use a free open source/commercial simulator which interfaces to the AOMF \begin_inset Index idx status collapsed \begin_layout Plain Layout AOMF, AOMF51 \end_layout \end_inset file (see \begin_inset CommandInset ref LatexCommand ref reference "OMF file" \end_inset ) optionally generated by SDCC. \end_layout \begin_layout Standard Debugging On-target: \end_layout \begin_layout Itemize use a MCU port pin to serially output debug data to the RS232 port of your host. You'll probably want some level shifting device typically involving a MAX232 or similar IC. If the hardware serial port of the MCU is not available search for 'Software UART' in your favourite search machine. \end_layout \begin_layout Itemize use an on-target monitor. In this context a monitor is a small program which usually accepts commands via a serial line and allows to set program counter, to single step through a program and read/write memory locations. For the 8051 good examples of monitors are paulmon and cmon51 (see section \begin_inset CommandInset ref LatexCommand ref reference "sec:Related-open-source-tools" \end_inset ). \end_layout \begin_layout Itemize toggle MCU port pins at strategic points within your code and use an oscilloscop e. A \emph on digital oscilloscope \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout Oscilloscope \end_layout \end_inset with deep trace memory is really helpful especially if you have to debug a realtime application. If you need to monitor more pins than your oscilloscope provides you can sometimes get away with a small R-2R network. On a single channel oscilloscope you could for example monitor 2 push-pull driven pins by connecting one via a 10 \begin_inset space ~ \end_inset k \begin_inset Formula $\Omega$ \end_inset resistor and the other one by a 5 \begin_inset space ~ \end_inset k \begin_inset Formula $\Omega$ \end_inset resistor to the oscilloscope probe (check output drive capability of the pins you want to monitor). If you need to monitor many more pins a \emph on logic analyzer \emph default will be handy. \end_layout \begin_layout Itemize use an ICE ( \emph on i \emph default n \emph on c \emph default ircuit \emph on e \emph default mulator \begin_inset Index idx status collapsed \begin_layout Plain Layout ICE (in circuit emulator) \end_layout \end_inset ). Usually very expensive. And very nice to have too. And usually locks you (for years...) to the devices the ICE can emulate. \end_layout \begin_layout Itemize use a remote debugger. In most 8-bit systems the symbol information is not available on the target, and a complete debugger is too bulky for the target system. Therefore usually a debugger on the host system connects to an on-target debugging stub which accepts only primitive commands. \begin_inset Newline newline \end_inset Terms to enter into your favourite search engine could be 'remote debugging', 'gdb stub' or 'inferior debugger'. (is there one?) \end_layout \begin_layout Itemize use an on target hardware debugger. Some of the more modern MCUs include hardware support for setting break points and monitoring/changing variables by using dedicated hardware pins. This facility doesn't require additional code to run on the target and \emph on usually \emph default doesn't affect runtime behaviour until a breakpoint is hit. For the mcs51 most hardware debuggers use the AOMF \begin_inset Index idx status collapsed \begin_layout Plain Layout AOMF, AOMF51 \end_layout \end_inset file (see \begin_inset CommandInset ref LatexCommand ref reference "OMF file" \end_inset ) as input file. \end_layout \begin_layout Standard Last not least: \end_layout \begin_layout Itemize if you are not familiar with any of the following terms you're likely to run into problems rather sooner than later: \emph on volatile \emph default , \emph on atomic \emph default , \emph on memory map \emph default , \emph on overlay \emph default . As an embedded programmer you \emph on have \emph default to know them so why not look them up \emph on before \emph default you have problems?) \end_layout \begin_layout Itemize tell someone else about your problem (actually this is a surprisingly effective means to hunt down the bug even if the listener is not familiar with your environment). As 'failure to communicate' is probably one of the job-induced deformations of an embedded programmer this is highly encouraged. \end_layout \begin_layout Section Debugging with SDCDB \begin_inset CommandInset label LatexCommand label name "cha:Debugging-with-SDCDB" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCDB (debugger) \end_layout \end_inset \end_layout \begin_layout Standard SDCC is distributed with a source level debugger \begin_inset Index idx status collapsed \begin_layout Plain Layout Debugger \end_layout \end_inset . The debugger uses a command line interface, the command repertoire of the debugger has been kept as close to gdb \begin_inset Index idx status collapsed \begin_layout Plain Layout gdb \end_layout \end_inset (the GNU debugger) as possible. The configuration and build process is part of the standard compiler installati on, which also builds and installs the debugger in the target directory specified during configuration. The debugger allows you debug BOTH at the C source and at the ASM source level. \end_layout \begin_layout Subsection Compiling for Debugging \end_layout \begin_layout Standard The - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug \end_layout \end_inset option must be specified for all files for which debug information is to be generated. The compiler generates a .adb file for each of these files. The linker creates the .cdb \begin_inset Index idx status collapsed \begin_layout Plain Layout .cdb \end_layout \end_inset file from the .adb \begin_inset Index idx status collapsed \begin_layout Plain Layout .adb \end_layout \end_inset files and the address information. This .cdb is used by the debugger. \end_layout \begin_layout Subsection How the Debugger Works \end_layout \begin_layout Standard When the - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -debug option is specified the compiler generates extra symbol information some of which are put into the assembler source and some are put into the .adb file. Then the linker creates the .cdb file from the individual .adb files with the address information for the symbols. The debugger reads the symbolic information generated by the compiler & the address information generated by the linker. It uses the SIMULATOR (Daniel's S51) to execute the program, the program execution is controlled by the debugger. When a command is issued for the debugger, it translates it into appropriate commands for the simulator. (Currently SDCDM only connects to the simulator but \emph on newcdb \emph default at \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://ec2drv.sourceforge.net/ \end_layout \end_inset is an effort to connect directly to the hardware.) \end_layout \begin_layout Subsection Starting the Debugger SDCDB \end_layout \begin_layout Standard The debugger can be started using the following command line. (Assume the file you are debugging has the file name foo). \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family sans \series bold sdcdb foo \begin_inset Newline newline \end_inset \family default \series default \begin_inset Newline newline \end_inset The debugger will look for the following files. \end_layout \begin_layout Itemize foo.c - the source file. \end_layout \begin_layout Itemize foo.cdb - the debugger symbol information file. \end_layout \begin_layout Itemize foo.ihx - the Intel hex format \begin_inset Index idx status collapsed \begin_layout Plain Layout Intel hex format \end_layout \end_inset object file. \end_layout \begin_layout Subsection SDCDB Command Line Options \end_layout \begin_layout Itemize - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -directory= this option can used to specify the directory search list. The debugger will look into the directory list specified for source, cdb & ihx files. The items in the directory list must be separated by ':', e.g. if the source files can be in the directories /home/src1 and /home/src2, the - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -directory option should be - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -directory=/home/src1:/home/src2. Note there can be no spaces in the option. \end_layout \begin_layout Itemize -cd - change to the . \end_layout \begin_layout Itemize -fullname - used by GUI front ends. \end_layout \begin_layout Itemize -cpu - this argument is passed to the simulator please see the simulator docs for details. \end_layout \begin_layout Itemize -X this options is passed to the simulator please see the simulator docs for details. \end_layout \begin_layout Itemize -s passed to simulator see the simulator docs for details. \end_layout \begin_layout Itemize -S passed to simulator see the simulator docs for details. \end_layout \begin_layout Itemize -k passed to simulator see the simulator docs for details. \end_layout \begin_layout Subsection SDCDB Debugger Commands \end_layout \begin_layout Standard As mentioned earlier the command interface for the debugger has been deliberatel y kept as close the GNU debugger gdb, as possible. This will help the integration with existing graphical user interfaces (like ddd, xxgdb or xemacs) existing for the GNU debugger. If you use a graphical user interface for the debugger you can skip this section. \end_layout \begin_layout Subsubsection* break [line | file:line | function | file:function] \end_layout \begin_layout Standard Set breakpoint at specified line or function: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family sans \series bold sdcdb>break 100 \begin_inset Newline newline \end_inset sdcdb>break foo.c:100 \begin_inset Newline newline \end_inset sdcdb>break funcfoo \begin_inset Newline newline \end_inset sdcdb>break foo.c:funcfoo \end_layout \begin_layout Subsubsection* clear [line | file:line | function | file:function ] \end_layout \begin_layout Standard Clear breakpoint at specified line or function: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family sans \series bold sdcdb>clear 100 \begin_inset Newline newline \end_inset sdcdb>clear foo.c:100 \begin_inset Newline newline \end_inset sdcdb>clear funcfoo \begin_inset Newline newline \end_inset sdcdb>clear foo.c:funcfoo \end_layout \begin_layout Subsubsection* continue \end_layout \begin_layout Standard Continue program being debugged, after breakpoint. \end_layout \begin_layout Subsubsection* finish \end_layout \begin_layout Standard Execute till the end of the current function. \end_layout \begin_layout Subsubsection* delete [n] \end_layout \begin_layout Standard Delete breakpoint number 'n'. If used without any option clear ALL user defined break points. \end_layout \begin_layout Subsubsection* info [break | stack | frame | registers ] \end_layout \begin_layout Itemize info break - list all breakpoints \end_layout \begin_layout Itemize info stack - show the function call stack. \end_layout \begin_layout Itemize info frame - show information about the current execution frame. \end_layout \begin_layout Itemize info registers - show content of all registers. \end_layout \begin_layout Subsubsection* step \end_layout \begin_layout Standard Step program until it reaches a different source line. Note: pressing repeats the last command. \end_layout \begin_layout Subsubsection* next \end_layout \begin_layout Standard Step program, proceeding through subroutine calls. \end_layout \begin_layout Subsubsection* run \end_layout \begin_layout Standard Start debugged program. \end_layout \begin_layout Subsubsection* ptype variable \end_layout \begin_layout Standard Print type information of the variable. \end_layout \begin_layout Subsubsection* print variable \end_layout \begin_layout Standard print value of variable. \end_layout \begin_layout Subsubsection* file filename \end_layout \begin_layout Standard load the given file name. Note this is an alternate method of loading file for debugging. \end_layout \begin_layout Subsubsection* frame \end_layout \begin_layout Standard print information about current frame. \end_layout \begin_layout Subsubsection* set srcmode \end_layout \begin_layout Standard Toggle between C source & assembly source. \end_layout \begin_layout Subsubsection* ! simulator command \end_layout \begin_layout Standard Send the string following '!' to the simulator, the simulator response is displayed. Note the debugger does not interpret the command being sent to the simulator, so if a command like 'go' is sent the debugger can loose its execution context and may display incorrect values. \end_layout \begin_layout Subsubsection* quit \end_layout \begin_layout Standard "Watch me now. Iam going Down. My name is Bobby Brown" \end_layout \begin_layout Subsection Interfacing SDCDB with DDD \end_layout \begin_layout Standard \begin_inset Note Note status collapsed \begin_layout Plain Layout The screenshot was converted from png to eps with: \begin_inset Quotes sld \end_inset bmeps -c -e8f -p3 ddd_example.png >ddd_example.eps \begin_inset Quotes srd \end_inset which produces a pretty compact eps file which is free from compression artifacts. \end_layout \begin_layout Plain Layout The screenshot was included in sdccman.lyx cvs version 1.120 but later removed as this broke the build system on Sourceforge (pdf-file was broken. pdflatex does not accept eps files). \end_layout \end_inset \end_layout \begin_layout Standard The \emph on p \emph default ortable \emph on n \emph default etwork \emph on g \emph default raphics File \size footnotesize \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/wiki_images/ddd_example.png \end_layout \end_inset \size default shows a screenshot of a debugging session with DDD \begin_inset Index idx status collapsed \begin_layout Plain Layout DDD (debugger) \end_layout \end_inset (Unix only) on a simulated 8032. The debugging session might not run as smoothly as the screenshot suggests. The debugger allows setting of breakpoints, displaying and changing variables, single stepping through C and assembler code. \begin_inset Newline newline \end_inset The source was compiled with \family sans \series bold \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset sdcc - \family default \series default \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \family sans \series bold -debug ddd_example.c \family default \series default \family sans \series bold \begin_inset Newline newline \end_inset \family default \series default \begin_inset Newline newline \end_inset and DDD was invoked with \family sans \series bold \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset ddd -debugger "sdcdb -cpu 8032 ddd_example" \end_layout \begin_layout Standard \begin_inset Note Note status collapsed \begin_layout Plain Layout Check that the double quotes or an apostrophe within the command line survive the \SpecialChar LyX tool chain. Previously the apostrophes got slanted in the PDF output so a cut and paste did not work. \end_layout \end_inset \end_layout \begin_layout Subsection Interfacing SDCDB with XEmacs \begin_inset Index idx status collapsed \begin_layout Plain Layout XEmacs \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Emacs \end_layout \end_inset \end_layout \begin_layout Standard Two files (in emacs lisp) are provided for the interfacing with XEmacs, sdcdb.el and sdcdbsrc.el. These two files can be found in the $(prefix)/bin directory after the installat ion is complete. These files need to be loaded into XEmacs for the interface to work. This can be done at XEmacs startup time by inserting the following into your '.xemacs' file (which can be found in your HOME directory): \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family typewriter (load-file sdcdbsrc.el) \family default \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset .xemacs is a lisp file so the () around the command is REQUIRED. The files can also be loaded dynamically while XEmacs is running, set the environment variable 'EMACSLOADPATH' to the installation bin directory (/bin), then enter the following command ESC-x load-file sdcdbsrc. To start the interface enter the following command: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family sans \series bold ESC-x sdcdbsrc \family default \series default \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset You will prompted to enter the file name to be debugged. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset The command line options that are passed to the simulator directly are bound to default values in the file sdcdbsrc.el. The variables are listed below, these values maybe changed as required. \end_layout \begin_layout Itemize sdcdbsrc-cpu-type '51 \end_layout \begin_layout Itemize sdcdbsrc-frequency '11059200 \end_layout \begin_layout Itemize sdcdbsrc-serial nil \end_layout \begin_layout Standard The following is a list of key mapping for the debugger interface. \end_layout \begin_layout Standard \begin_inset space ~ \end_inset \family typewriter \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset Current Listing :: \begin_inset Newline newline \end_inset ;;key \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset binding \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset Comment \begin_inset Newline newline \end_inset ;;--- \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ------- \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ------- \begin_inset Newline newline \end_inset ;; \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset n \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdb-next-from-src \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset SDCDB next command \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset b \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdb-back-from-src \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset SDCDB back command \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset c \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdb-cont-from-src \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset SDCDB continue command \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset s \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdb-step-from-src \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset SDCDB step command \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset ? \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdb-whatis-c-sexp \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset SDCDB ptypecommand for data at \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset buffer point \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset x \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdbsrc-delete \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset SDCDB Delete all breakpoints if no arg \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset given or delete arg (C-u arg x) \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset m \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdbsrc-frame \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset SDCDB Display current frame if no arg, \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset given or display frame arg \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset buffer point \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset ! \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdbsrc-goto-sdcdb \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset Goto the SDCDB output buffer \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset p \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdb-print-c-sexp \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset SDCDB print command for data at \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset buffer point \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset g \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdbsrc-goto-sdcdb \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset Goto the SDCDB output buffer \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset t \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdbsrc-mode \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset Toggles Sdcdbsrc mode (turns it off) \begin_inset Newline newline \end_inset ;; \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset C-c \begin_inset space ~ \end_inset C-f \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdb-finish-from-src \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset SDCDB finish command \begin_inset Newline newline \end_inset ;; \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset C-x \begin_inset space ~ \end_inset SPC \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdb-break \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset Set break for line with point \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset ESC \begin_inset space ~ \end_inset t \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdbsrc-mode \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset Toggle Sdcdbsrc mode \begin_inset Newline newline \end_inset ;; \begin_inset space ~ \end_inset ESC \begin_inset space ~ \end_inset m \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sdcdbsrc-srcmode \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset Toggle list mode \begin_inset Newline newline \end_inset ;; \end_layout \begin_layout Chapter TIPS \end_layout \begin_layout Standard Here are a few guidelines that will help the compiler generate more efficient code, some of the tips are specific to this compiler others are generally good programming practice. \end_layout \begin_layout Itemize Use the smallest data type to represent your data-value. If it is known in advance that the value is going to be less than 256 then use an 'unsigned char' instead of a 'short' or 'int'. Please note, that ANSI C requires both signed and unsigned chars to be promoted to 'signed int' \begin_inset Index idx status collapsed \begin_layout Plain Layout promotion to signed int \end_layout \end_inset \begin_inset Marginal status collapsed \begin_layout Plain Layout \series bold \begin_inset space ~ \end_inset ! \end_layout \end_inset before doing any operation. This promotion \begin_inset Index idx status collapsed \begin_layout Plain Layout type promotion \end_layout \end_inset \begin_inset CommandInset label LatexCommand label name "type promotion" \end_inset can be omitted, if the result is the same. The effect of the promotion rules together with the sign-extension is often surprising: \begin_inset Separator latexpar \end_inset \end_layout \begin_deeper \begin_layout Verse \family typewriter unsigned char uc = 0xfe; \begin_inset Newline newline \end_inset if (uc * uc < 0) /* this is true! */ \begin_inset Newline newline \end_inset { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .... \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard \family typewriter uc * uc \family default is evaluated as \family typewriter (int) uc * (int) uc = (int) 0xfe * (int) 0xfe = (int) 0xfc04 = -1024 \family default . \begin_inset Newline newline \end_inset Another one: \end_layout \begin_layout Verse \family typewriter (unsigned char) -12 / (signed char) -3 = ... \end_layout \begin_layout Standard No, the result is not 4: \end_layout \begin_layout Verse \family typewriter (int) (unsigned char) -12 / (int) (signed char) -3 = \begin_inset Newline newline \end_inset (int) (unsigned char) 0xf4 / (int) (signed char) 0xfd = \begin_inset Newline newline \end_inset (int) 0x00f4 / (int) 0xfffd = \begin_inset Newline newline \end_inset (int) 0x00f4 / (int) 0xfffd = \begin_inset Newline newline \end_inset (int) 244 / (int) -3 = \begin_inset Newline newline \end_inset (int) -81 = (int) 0xffaf; \end_layout \begin_layout Standard Don't complain, that gcc gives you a different result. gcc uses 32 bit ints, while SDCC uses 16 bit ints. Therefore the results are different. \begin_inset Newline newline \end_inset From \begin_inset Quotes sld \end_inset comp.lang.c FAQ \begin_inset Quotes srd \end_inset : \end_layout \begin_layout Quote \emph on If well-defined overflow characteristics are important and negative values are not, or if you want to steer clear of sign-extension problems when manipulating bits or bytes, use one of the corresponding unsigned types. (Beware when mixing signed and unsigned values in expressions, though.) \begin_inset Newline newline \end_inset Although character types (especially unsigned char) can be used as "tiny" integers, doing so is sometimes more trouble than it's worth, due to unpredicta ble sign extension and increased code size. \end_layout \end_deeper \begin_layout Itemize Use unsigned when it is known in advance that the value is not going to be negative. This helps especially if you are doing division or multiplication, bit-shifting or are using an array index. \end_layout \begin_layout Itemize NEVER jump into a LOOP. \end_layout \begin_layout Itemize Declare the variables to be local \begin_inset Index idx status collapsed \begin_layout Plain Layout local variables \end_layout \end_inset whenever possible, especially loop control variables (induction). \end_layout \begin_layout Itemize Have a look at the assembly listing to get a \begin_inset Quotes sld \end_inset feeling \begin_inset Quotes srd \end_inset for the code generation. \end_layout \begin_layout Section Porting code from or to other compilers \begin_inset CommandInset label LatexCommand label name "sec:Porting-code-to-other-compilers" \end_inset \end_layout \begin_layout Itemize check whether endianness \begin_inset Index idx status collapsed \begin_layout Plain Layout Endianness \end_layout \end_inset of the compilers differs and adapt where needed. \end_layout \begin_layout Itemize check the device specific header files \begin_inset Index idx status collapsed \begin_layout Plain Layout Header files \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Include files \end_layout \end_inset for compiler specific syntax. Eventually include the file \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://svn.code.sf.net/p/sdcc/code/trunk/sdcc/device/include/mcs51/compiler.h \end_layout \end_inset to allow using common header files. (see f.e. cc2510fx.h \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://svn.code.sf.net/p/sdcc/code/trunk/sdcc/device/include/mcs51/cc2510fx.h \end_layout \end_inset ). \end_layout \begin_layout Itemize check whether the startup code contains the correct initialization (watchdog \begin_inset Index idx status collapsed \begin_layout Plain Layout watchdog \end_layout \end_inset , peripherals). \end_layout \begin_layout Itemize check whether the sizes of short, int, long match. \end_layout \begin_layout Itemize check if some 16 or 32 bit hardware registers require a specific addressing order (least significant or most significant byte first) and adapt if needed ( \emph on first \emph default and \emph on last \emph default relate to time and not to lower/upper memory location here, so this is \emph on not \emph default the same as endianness). \end_layout \begin_layout Itemize check whether the keyword \emph on volatile \begin_inset Index idx status collapsed \begin_layout Plain Layout volatile \end_layout \end_inset \emph default is used where needed. The compilers might differ in their optimization characteristics (as different versions of the same compiler might also use more clever optimizations this is good idea anyway). See section \begin_inset CommandInset ref LatexCommand ref reference "subsec:Common-interrupt-pitfall-volatile" \end_inset . \end_layout \begin_layout Itemize check that the compilers are not told to suppress warnings. \end_layout \begin_layout Itemize check and convert compiler specific extensions (interrupts, memory areas, pragmas etc.). \end_layout \begin_layout Itemize check for differences in type promotion. Especially check for math operations on \family typewriter char \family default or \family typewriter unsigned char \family default variables. For the sake of C99 compatibility SDCC will probably promote these to \family typewriter int \family default more often than other compilers. Eventually insert explicit casts to \family typewriter (char) \family default or \family typewriter (unsigned char) \family default . Also check that the ~ \begin_inset space ~ \end_inset operator \begin_inset Index idx status collapsed \begin_layout Plain Layout ~ Operator \end_layout \end_inset is not used on \family typewriter bit \begin_inset Index idx status collapsed \begin_layout Plain Layout bit \end_layout \end_inset \family default variables, use the ! \begin_inset space ~ \end_inset operator instead. See sections \begin_inset CommandInset ref LatexCommand ref reference "type promotion" \end_inset and \begin_inset CommandInset ref LatexCommand ref reference "sec:Compatibility-with-previous" \end_inset . \end_layout \begin_layout Itemize check the assembly code generated for interrupt routines (f.e. for calls to possibly non-reentrant library functions). \end_layout \begin_layout Itemize check whether timing loops result in proper timing (or preferably consider a rewrite of the code with timer based delays instead). \end_layout \begin_layout Itemize check for differences in printf parameters \begin_inset Index idx status collapsed \begin_layout Plain Layout printf()!parameters \end_layout \end_inset (some compilers push (va_arg \begin_inset Index idx status collapsed \begin_layout Plain Layout vararg, va \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash _ \end_layout \end_inset arg \end_layout \end_inset ) char variables as \family typewriter int \family default others push them as \family typewriter char \family default . See section \begin_inset CommandInset ref LatexCommand ref reference "sec:Compatibility-with-previous" \end_inset ). Provide a putchar() \begin_inset Index idx status collapsed \begin_layout Plain Layout printf()!putchar() \end_layout \end_inset function if needed. \end_layout \begin_layout Itemize check the resulting memory map \begin_inset Index idx status collapsed \begin_layout Plain Layout Memory map \end_layout \end_inset . Usage of different memory spaces: code, stack, data (for mcs51/ds390 additional ly idata, pdata, xdata). Eventually check if unexpected library functions are included. \end_layout \begin_layout Section Tools \begin_inset Index idx status collapsed \begin_layout Plain Layout Tools \end_layout \end_inset included in the distribution \end_layout \begin_layout Standard \align left \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout \series bold Name \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold Purpose \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold Directory \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout as2gbmap.py \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout sdas map to rrgb map and no$gmb sym file format converter \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout sdcc/support/scripts \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout cinc2h.pl \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout gpasm inc to c header file converter \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout sdcc/support/scripts \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout gen_known_bugs.pl \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout generate knownbugs.html \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout sdcc/support/scripts \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout keil2sdcc.pl \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Keil header \begin_inset Index idx status collapsed \begin_layout Plain Layout Header files \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Include files \end_layout \end_inset to SDCC header file converter \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout sdcc/support/scripts \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout makebin \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Intel Hex to binary and GameBoy binay format converter \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \family roman \series medium \shape up \size normal \emph off \bar no \noun off \color none sdcc/bin \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout mcs51-disasm.pl \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout disassembler to the mcs51 instructions contained hex files \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout sdcc/support/scripts \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout mh2h.c \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout header file conversion \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout sdcc/support/scripts \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout optimize_pic16devices.pl \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout optimizes or unoptimizes the pic16devices.txt 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\end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.open-std.org/jtc1/sc22/wg14/www/standards.html#9899 \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout ISO/IEC DTR 18037 \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \begin_inset Quotes sld \end_inset Extensions for Embedded C \begin_inset Quotes srd \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1021.pdf \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Latest datasheet of target CPU \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout vendor \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout Revision history of datasheet \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout vendor \end_layout \end_inset \end_inset \end_layout \begin_layout Section Application notes specifically for SDCC \end_layout \begin_layout Standard SDCC makes no claims about the completeness of this list and about up-to-datenes s or correctness of the application notes \begin_inset Index idx status collapsed \begin_layout Plain Layout Application notes \end_layout \end_inset . \begin_inset Separator latexpar \end_inset \end_layout \begin_layout Standard \align left \size footnotesize \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout \series bold \size footnotesize Vendor \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold \size footnotesize Subject / Title \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold \size footnotesize Where to get \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Maxim / Dallas \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Using the SDCC Compiler for the DS80C400 \begin_inset Index idx status collapsed \begin_layout Plain Layout DS80C400 \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://pdfserv.maxim-ic.com/en/an/AN3346.pdf \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Maxim / Dallas \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Using the Free SDCC C Compiler to Develop Firmware for the DS89C420/430/440/450 \begin_inset Index idx status collapsed \begin_layout Plain Layout DS89C4x0 \end_layout \end_inset Family of Microcontrollers \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://pdfserv.maxim-ic.com/en/an/AN3477.pdf \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Silicon Laboratories / Cygnal \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Integrating SDCC 8051 Tools Into The Silicon Labs IDE \begin_inset Index idx status collapsed \begin_layout Plain Layout IDE \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.silabs.com/public/documents/tpub_doc/anote/Microcontrollers/en/an198.pdf \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Ramtron / Goal Semiconductor \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Interfacing SDCC to Syn and Textpad \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.ramtron.com/doc/Products/Microcontroller/Support_Tools.asp \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Ramtron / Goal Semiconductor \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Installing and Configuring SDCC and Crimson Editor \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.ramtron.com/doc/Products/Microcontroller/Support_Tools.asp \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Texas Instruments \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize MSC12xx Programming with SDCC \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://focus.ti.com/general/docs/lit/getliterature.tsp?literatureNumber=sbaa109&fil eType=pdf \end_layout \end_inset \end_layout \end_inset \end_inset \end_layout \begin_layout Section Some Questions \end_layout \begin_layout Standard Some questions answered, some pointers given - it might be time to in turn ask \emph on you \emph default some questions: \end_layout \begin_layout Itemize can you solve your project with the selected microcontroller? Would you find out early or rather late that your target is too small/slow/whatever? Can you switch to a slightly better device if it doesn't fit? \end_layout \begin_layout Itemize should you solve the problem with an 8 bit CPU? Or would a 16/32 bit CPU and/or another programming language be more adequate? Would an operating system on the target device help? \end_layout \begin_layout Itemize if you solved the problem, will the marketing department be happy? \end_layout \begin_layout Itemize if the marketing department is happy, will customers be happy? \end_layout \begin_layout Itemize if you're the project manager, marketing department and maybe even the customer in one person, have you tried to see the project from the outside? \end_layout \begin_layout Itemize is the project done if you think it is done? Or is just that other interface/pro tocol/feature/configuration/option missing? How about website, manual(s), internationali(z|s)ation, packaging, labels, 2nd source for components, electromagnetic compatability/interference, documentation for production, production test software, update mechanism, patent issues? \end_layout \begin_layout Itemize is your project adequately positioned in that magic triangle: fame, fortune, fun? \end_layout \begin_layout Standard Maybe not all answers to these questions are known and some answers may even be \emph on no \emph default , nevertheless knowing these questions may help you to avoid burnout \begin_inset Foot status collapsed \begin_layout Plain Layout burnout is bad for electronic devices, programmers and motorcycle tyres \end_layout \end_inset . Chances are you didn't want to hear some of them... \end_layout \begin_layout Chapter Support \begin_inset Index idx status collapsed \begin_layout Plain Layout Support \end_layout \end_inset \end_layout \begin_layout Standard SDCC has grown to be a large project. The compiler alone (without the preprocessor, assembler and linker) is well over 150,000 lines of code (blank stripped). The open source nature of this project is a key to its continued growth and support. You gain the benefit and support of many active software developers and end users. Is SDCC perfect? No, that's why we need your help. The developers take pride in fixing reported bugs. You can help by reporting the bugs and helping other SDCC users. There are lots of ways to contribute, and we encourage you to take part in making SDCC a great software package. \end_layout \begin_layout Standard The SDCC project is hosted on the SDCC SourceForge site at \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/projects/sdcc \end_layout \end_inset . You'll find the complete set of mailing lists \begin_inset Index idx status collapsed \begin_layout Plain Layout Mailing list(s) \end_layout \end_inset , forums, bug reporting system, patch submission \begin_inset Index idx status open \begin_layout Plain Layout Patch submission \end_layout \end_inset system, wiki, rss-feed, download \begin_inset Index idx status collapsed \begin_layout Plain Layout download \end_layout \end_inset area and Subversion code repository \begin_inset Index idx status collapsed \begin_layout Plain Layout Subversion code repository \end_layout \end_inset there. \end_layout \begin_layout Section Reporting Bugs \begin_inset Index idx status collapsed \begin_layout Plain Layout Bug reporting \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Reporting bugs \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Communication!Bug report \end_layout \end_inset \end_layout \begin_layout Standard The recommended way of reporting bugs is using the infrastructure of the SourceForge site. You can follow the status of bug reports there and have an overview about the known bugs. \end_layout \begin_layout Standard Bug reports are automatically forwarded to the developer mailing list and will be fixed ASAP. When reporting a bug, it is very useful to include a small test program (the smaller the better) which reproduces the problem. If you can isolate the problem by looking at the generated assembly code, this can be very helpful. Compiling your program with the - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -dumpall \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -dumpall \end_layout \end_inset option can sometimes be useful in locating optimization problems. When reporting a bug please make sure you: \end_layout \begin_layout Enumerate Attach the code you are compiling with SDCC. \end_layout \begin_layout Enumerate Specify the exact command you use to run SDCC, or attach your Makefile. \end_layout \begin_layout Enumerate Specify the SDCC version (type " \family sans \series bold sdcc -v \family default \series default "), your platform, and operating system. \end_layout \begin_layout Enumerate Provide an exact copy of any error message or incorrect output. \end_layout \begin_layout Enumerate Put something meaningful in the subject of your message. \end_layout \begin_layout Standard Please attempt to include these 5 important parts, as applicable, in all requests for support or when reporting any problems or bugs with SDCC. Though this will make your message lengthy, it will greatly improve your chance that SDCC users and developers will be able to help you. Some SDCC developers are frustrated by bug reports without code provided that they can use to reproduce and ultimately fix the problem, so please be sure to provide sample code if you are reporting a bug! \end_layout \begin_layout Standard Please have a short check that you are using a recent version of SDCC and the bug is not yet known. This is the link for reporting bugs: \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/p/sdcc/bugs/ \end_layout \end_inset . With SDCC on average having more than 200 downloads \begin_inset Index idx status collapsed \begin_layout Plain Layout download \end_layout \end_inset on SourceForge per day \begin_inset Foot status collapsed \begin_layout Plain Layout 220 daily downloads on average Jan-Sept 2006 and about 150 daily downloads between 2002 and 2005. This does not include other methods of distribution. \end_layout \end_inset there must be some users. So it's not exactly easy to find a new bug. If you find one we need it: \emph on reporting bugs is good \emph default . \end_layout \begin_layout Section Requesting Features \begin_inset CommandInset label LatexCommand label name "subsec:Requesting-Features" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Feature request \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Requesting features \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Communication!Feature request \end_layout \end_inset \end_layout \begin_layout Standard Like bug reports feature requests are forwarded to the developer mailing list. This is the link for requesting features: \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/p/sdcc/feature-requests/ \end_layout \end_inset . \end_layout \begin_layout Section Submitting patches \begin_inset Index idx status collapsed \begin_layout Plain Layout Communication!Patch submission \end_layout \end_inset \end_layout \begin_layout Standard Like bug reports contributed patches are forwarded to the developer mailing list. This is the link for submitting patches \begin_inset Index idx status collapsed \begin_layout Plain Layout Patch submission \end_layout \end_inset : \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/p/sdcc/patches/ \end_layout \end_inset . \end_layout \begin_layout Standard You need to specify some parameters to the \family typewriter diff \family default command for the patches to be useful. If you modified more than one file a patch created f.e. with \family sans \series bold \begin_inset Quotes sld \end_inset diff -Naur unmodified_directory modified_directory >my_changes.patch \begin_inset Quotes srd \end_inset \family default \series default will be fine, otherwise \family sans \series bold \begin_inset Quotes sld \end_inset diff -u sourcefile.c.orig sourcefile.c >my_changes.patch \begin_inset Quotes srd \end_inset \family default \series default will do. \end_layout \begin_layout Section Getting Help \end_layout \begin_layout Standard These links should take you directly to the Mailing lists \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/p/sdcc/mailman/sdcc-user/ \end_layout \end_inset \begin_inset Foot status collapsed \begin_layout Plain Layout Traffic on sdcc-devel and sdcc-user is about 100 mails/month each not counting automated messages (mid 2003) \end_layout \end_inset and the Forums \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/p/sdcc/discussion/ \end_layout \end_inset , lists \begin_inset Index idx status collapsed \begin_layout Plain Layout Mailing list(s) \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Communication!Mailing lists \end_layout \end_inset and forums are archived and searchable so if you are lucky someone already had a similar problem. While mails to the lists themselves are delivered promptly their web front end on SourceForge sometimes shows a severe time lag (up to several weeks), if you're seriously using SDCC please consider subscribing to the lists. \end_layout \begin_layout Section ChangeLog \end_layout \begin_layout Standard You can follow the status of the Subversion version \begin_inset Index idx status collapsed \begin_layout Plain Layout version \end_layout \end_inset of SDCC by watching the Changelog \begin_inset Index idx status collapsed \begin_layout Plain Layout Changelog \end_layout \end_inset in the Subversion repository \size footnotesize \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://svn.code.sf.net/p/sdcc/code/trunk/sdcc/ChangeLog \end_layout \end_inset . \end_layout \begin_layout Section Subversion Source Code Repository \end_layout \begin_layout Standard The output of \family sans \series bold sdcc - \family default \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \family sans -version \family default \series default or the filenames of the snapshot versions of SDCC include date and its Subversion \begin_inset Index idx status collapsed \begin_layout Plain Layout Subversion code repository \end_layout \end_inset number. Subversion allows to download the source of recent or previous versions \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/p/sdcc/code/8805/tree/ \end_layout \end_inset (by number or by date). \end_layout \begin_layout Section Release policy \begin_inset Index idx status collapsed \begin_layout Plain Layout Release policy \end_layout \end_inset \end_layout \begin_layout Standard Starting with version 2.4.0 SDCC in 2004 uses a time-based release schedule with one official release usually during the first half of the year. \end_layout \begin_layout Standard The last digit of an official release is zero. Additionally there are daily snapshots available at \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/snap.php \end_layout \end_inset , and you can always build the very last version from the source code available at Sourceforge \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/snap.php#Source \end_layout \end_inset . The SDCC Wiki \begin_inset Index idx status collapsed \begin_layout Plain Layout wiki \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout SDCC Wiki \end_layout \end_inset at \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/wiki/ \end_layout \end_inset also holds some information about past and future releases. \end_layout \begin_layout Section Quality control \begin_inset CommandInset label LatexCommand label name "sec:Quality-control" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Quality control \end_layout \end_inset \end_layout \begin_layout Standard The compiler is passed through \shape italic daily \shape default snapshot build compile and build checks. The so called \shape italic regression tests \shape default \begin_inset Index idx status collapsed \begin_layout Plain Layout Regression test \end_layout \end_inset check that SDCC itself compiles flawlessly on several host platforms (i386, Opteron, 64 bit Alpha, ppc64, Mac OS X on ppc and i386, Solaris on Sparc) and checks the quality of the code generated by SDCC by running the code for several target platforms through simulators. The regression test suite comprises about 1000 files which expand to more than 1500 test cases which include about 7000 tests. A large number of tests from the GCC test suite is included in this. The results of these tests are published daily on SDCC's snapshot page (click on the red or green symbols on the right side of \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/snap.php \end_layout \end_inset ). \end_layout \begin_layout Standard You'll find the test code in the directory \shape italic sdcc/support/regression \shape default . You can run these tests manually by running \family sans make \family default in this directory (or f.e. \family sans \series bold \begin_inset Quotes sld \end_inset make test-mcs51 \begin_inset Quotes srd \end_inset \family default \series default if you don't want to run the complete tests). The test code might also be interesting if you want to look for examples \begin_inset Index idx status collapsed \begin_layout Plain Layout Examples \end_layout \end_inset checking corner cases of SDCC or if you plan to submit patches \begin_inset Index idx status collapsed \begin_layout Plain Layout Patch submission \end_layout \end_inset . \end_layout \begin_layout Standard The PIC14 port uses a different set of regression tests \begin_inset Index idx status collapsed \begin_layout Plain Layout Regression test (PIC14) \end_layout \end_inset , you'll find them in the directory \shape italic sdcc/src/regression \shape default . \end_layout \begin_layout Section Examples \begin_inset Index idx status collapsed \begin_layout Plain Layout Examples \end_layout \end_inset \end_layout \begin_layout Standard You'll find some small examples in the directory \emph on sdcc/device/examples/. \emph default More examples and libraries are available at \emph on The SDCC Open Knowledge Resource \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdccokr.dl9sec.de/ \end_layout \end_inset \emph default web site or at \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.pjrc.com/tech/8051/ \end_layout \end_inset . \end_layout \begin_layout Standard \begin_inset Note Note status collapsed \begin_layout Plain Layout I did insert a reference to Paul's web site here although it seems rather dedicated to a specific 8032 board (I think it's okay because it f.e. shows LCD/Harddisc interface and has a free 8051 monitor. Independent 8032 board vendors face hard competition of heavily subsidized development boards anyway). \end_layout \begin_layout Plain Layout Maybe we should include some links to real world applications. Preferably pointer to pointers (one for each architecture) so this stays manageable here? \end_layout \end_inset \end_layout \begin_layout Section Use of SDCC in Education \end_layout \begin_layout Standard In short: \emph on highly \emph default encouraged \begin_inset Foot status collapsed \begin_layout Plain Layout the phrase "use in education" might evoke the association " \emph on only \emph default fit for use in education". This connotation is not intended but nevertheless risked as the licensing of SDCC makes it difficult to offer educational discounts \end_layout \end_inset . If your rationales are to: \end_layout \begin_layout Enumerate give students a chance to understand the \emph on complete \emph default steps of code generation \end_layout \begin_layout Enumerate have a curriculum that can be extended for years. Then you could use an FPGA board as target and your curriculum will seamlessly extend from logic synthesis (http://www.opencores.org \begin_inset Flex URL status collapsed \begin_layout Plain Layout opencores.org \end_layout \end_inset , Oregano \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.oregano.at/ip/ip01.htm \end_layout \end_inset ), over assembly programming, to C to FPGA compilers (FPGAC \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/projects/fpgac/ \end_layout \end_inset ) and to C. \end_layout \begin_layout Enumerate be able to insert excursions about skills like using a revision control system, submitting/applying patches, using a type-setting (as opposed to word-processing) engine \SpecialChar LyX /\SpecialChar LaTeX , using SourceForge \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/ \end_layout \end_inset , following some netiquette \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://en.wikipedia.org/wiki/Netiquette \end_layout \end_inset , understanding BSD/LGPL/GPL/Proprietary licensing, growth models of Open Source Software, CPU simulation, compiler regression tests \begin_inset Index idx status collapsed \begin_layout Plain Layout Regression test \end_layout \end_inset . \begin_inset Newline newline \end_inset And if there should be a shortage of ideas then you can always point students to the ever-growing feature request list \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/p/sdcc/feature-requests/ \end_layout \end_inset . \end_layout \begin_layout Enumerate not tie students to a specific host platform and instead allow them to use a host platform of \emph on their \emph default choice (among them Alpha, i386, i386_64, Mac OS X, Mips, Sparc, Windows and eventually OLPC \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://www.laptop.org \end_layout \end_inset ) \end_layout \begin_layout Enumerate not encourage students to use illegal copies of educational software \end_layout \begin_layout Enumerate be immune to licensing/availability/price changes of the chosen tool chain \end_layout \begin_layout Enumerate be able to change to a new target platform without having to adopt a new tool chain \end_layout \begin_layout Enumerate have complete control over and insight into the tool chain \end_layout \begin_layout Enumerate make your students aware about the pros and cons of open source software development \end_layout \begin_layout Enumerate give back to the public as you are probably at least partially publicly funded \end_layout \begin_layout Enumerate give students a chance to publicly prove their skills and to possibly see a world wide impact \end_layout \begin_layout Standard then SDCC is probably among the first choices. Well, probably SDCC might be the only choice. \end_layout \begin_layout Chapter SDCC Technical Data \end_layout \begin_layout Section Optimizations \begin_inset Index idx status collapsed \begin_layout Plain Layout Optimizations \end_layout \end_inset \end_layout \begin_layout Standard SDCC performs a host of standard optimizations in addition to some MCU specific optimizations. \end_layout \begin_layout Subsection Sub-expression Elimination \begin_inset Index idx status collapsed \begin_layout Plain Layout Subexpression elimination \end_layout \end_inset \end_layout \begin_layout Standard The compiler does local and \emph on g \emph default lobal \emph on c \emph default ommon \emph on s \emph default ubexpression \emph on e \emph default limination, e.g.: \end_layout \begin_layout Verse \family typewriter i = x + y + 1; \begin_inset Newline newline \end_inset j = x + y; \end_layout \begin_layout Standard will be translated to \end_layout \begin_layout Verse \family typewriter iTemp = x + y; \begin_inset Newline newline \end_inset i = iTemp + 1; \begin_inset Newline newline \end_inset j = iTemp; \end_layout \begin_layout Standard Some subexpressions are not as obvious as the above example, e.g.: \end_layout \begin_layout Verse \family typewriter a->b[i].c = 10; \begin_inset Newline newline \end_inset a->b[i].d = 11; \end_layout \begin_layout Standard In this case the address arithmetic a->b[i] will be computed only once; the equivalent code in C would be. \end_layout \begin_layout Verse \family typewriter iTemp = a->b[i]; \begin_inset Newline newline \end_inset iTemp.c = 10; \begin_inset Newline newline \end_inset iTemp.d = 11; \end_layout \begin_layout Standard The compiler will try to keep these temporary variables in registers. \end_layout \begin_layout Subsection Dead-Code Elimination \begin_inset Index idx status open \begin_layout Plain Layout Dead-code elimination \end_layout \end_inset \end_layout \begin_layout Verse \family typewriter int global; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset void f () { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset int i; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset i = 1; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* dead store */ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset global = 1; \begin_inset space ~ \end_inset /* dead store */ \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset global = 2; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset return; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset global = 3; \begin_inset space ~ \end_inset /* unreachable */ \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard will be changed to \end_layout \begin_layout Verse \family typewriter int global; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset void f () { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset global = 2; \begin_inset Newline newline \end_inset } \end_layout \begin_layout Subsection Copy-Propagation \begin_inset Index idx status collapsed \begin_layout Plain Layout Copy propagation \end_layout \end_inset \end_layout \begin_layout Verse \family typewriter int f() { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset int i, j; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset i = 10; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset j = i; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset return j; \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard will be changed to \end_layout \begin_layout Verse \family typewriter int f() { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset int i, j; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset i = 10; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset j = 10; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset return 10; \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard Note: the dead stores created by this copy propagation will be eliminated by dead-code elimination. \end_layout \begin_layout Subsection Loop Optimizations \begin_inset Index idx status collapsed \begin_layout Plain Layout Loop optimization \end_layout \end_inset \begin_inset CommandInset label LatexCommand label name "subsec:Loop-Optimizations" \end_inset \end_layout \begin_layout Standard Two types of loop optimizations are done by SDCC \emph on loop invariant \emph default lifting and \emph on strength reduction \emph default of loop induction variables. In addition to the strength reduction the optimizer marks the induction variables and the register allocator tries to keep the induction variables in registers for the duration of the loop. Because of this preference of the register allocator \begin_inset Index idx status collapsed \begin_layout Plain Layout Register allocation \end_layout \end_inset , loop induction optimization causes an increase in register pressure, which may cause unwanted spilling of other temporary variables into the stack \begin_inset Index idx status collapsed \begin_layout Plain Layout stack \end_layout \end_inset / data space. The compiler will generate a warning message when it is forced to allocate extra space either on the stack or data space. If this extra space allocation is undesirable then induction optimization can be eliminated either for the entire source file (with - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -noinduction option) or for a given function only using #pragma \begin_inset space ~ \end_inset noinduction \begin_inset Index idx status collapsed \begin_layout Plain Layout \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash # \end_layout \end_inset pragma noinduction \end_layout \end_inset . \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Loop Invariant: \end_layout \begin_layout Verse \family typewriter for (i = 0 ; i < 100 ; i ++) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset f += k + l; \end_layout \begin_layout Standard changed to \end_layout \begin_layout Verse \family typewriter itemp = k + l; \begin_inset Newline newline \end_inset for (i = 0; i < 100; i++) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset f += itemp; \end_layout \begin_layout Standard As mentioned previously some loop invariants are not as apparent, all static address computations are also moved out of the loop. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Strength Reduction \begin_inset Index idx status collapsed \begin_layout Plain Layout Strength reduction \end_layout \end_inset , this optimization substitutes an expression by a cheaper expression: \end_layout \begin_layout Verse \family typewriter for (i=0;i < 100; i++) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ar[i*5] = i*3; \end_layout \begin_layout Standard changed to \end_layout \begin_layout Verse \family typewriter itemp1 = 0; \begin_inset Newline newline \end_inset itemp2 = 0; \begin_inset Newline newline \end_inset for (i=0;i< 100;i++) { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ar[itemp1] = itemp2; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset itemp1 += 5; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset itemp2 += 3; \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard The more expensive multiplication \begin_inset Index idx status collapsed \begin_layout Plain Layout Multiplication \end_layout \end_inset is changed to a less expensive addition. \end_layout \begin_layout Subsection Loop Reversing \begin_inset Index idx status collapsed \begin_layout Plain Layout Loop reversing \end_layout \end_inset \end_layout \begin_layout Standard This optimization is done to reduce the overhead of checking loop boundaries for every iteration. Some simple loops can be reversed and implemented using a \begin_inset Quotes eld \end_inset decrement and jump if not zero \begin_inset Quotes erd \end_inset instruction. SDCC checks for the following criterion to determine if a loop is reversible (note: more sophisticated compilers use data-dependency analysis to make this determination, SDCC uses a more simple minded analysis). \end_layout \begin_layout Itemize The 'for' loop is of the form \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \family typewriter for( = ; [< | <=] ; [++ | += 1]) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \end_layout \begin_layout Itemize The does not contain \begin_inset Quotes eld \end_inset continue \begin_inset Quotes erd \end_inset or 'break \begin_inset Quotes erd \end_inset . \end_layout \begin_layout Itemize All goto's are contained within the loop. \end_layout \begin_layout Itemize No function calls within the loop. \end_layout \begin_layout Itemize The loop control variable is not assigned any value within the loop \end_layout \begin_layout Itemize The loop control variable does NOT participate in any arithmetic operation within the loop. \end_layout \begin_layout Itemize There are NO switch statements in the loop. \end_layout \begin_layout Subsection Algebraic Simplifications \end_layout \begin_layout Standard SDCC does numerous algebraic simplifications, the following is a small sub-set of these optimizations. \end_layout \begin_layout Verse \family typewriter i = j + 0; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* changed to: */ \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset i = j; \begin_inset Newline newline \end_inset i /= 2; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* for unsigned i changed to: */ \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset i >>= 1; \begin_inset Newline newline \end_inset i = j - j; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* changed to: */ \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset i = 0; \begin_inset Newline newline \end_inset i = j / 1; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* changed to: */ \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset i = j; \end_layout \begin_layout Standard Note the subexpressions \begin_inset Index idx status collapsed \begin_layout Plain Layout Subexpression \end_layout \end_inset given above are generally introduced by macro expansions or as a result of copy/constant propagation. \end_layout \begin_layout Subsection 'switch' Statements \begin_inset CommandInset label LatexCommand label name "subsec:'switch'-Statements" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout switch statement \end_layout \end_inset \end_layout \begin_layout Standard SDCC can optimize switch statements to jump tables \begin_inset Index idx status collapsed \begin_layout Plain Layout jump tables \end_layout \end_inset . It makes the decision based on an estimate of the generated code size. SDCC is quite liberal in the requirements for jump table generation: \end_layout \begin_layout Itemize The labels need not be in order, and the starting number need not be one or zero, the case labels are in numerical sequence or not too many case labels are missing. \begin_inset Separator latexpar \end_inset \end_layout \begin_deeper \begin_layout Verse \family typewriter switch(i) { \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset switch (i) { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 4: ... \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 0: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 5: ... \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 1: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 3: ... \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 6: ... \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 3: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 7: ... \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 4: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 8: ... \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 5: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 9: ... \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 6: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 10: ... \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 7: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 11: ... \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 8: ... \begin_inset Newline newline \end_inset } \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset } \end_layout \begin_layout Standard Both the above switch statements will be implemented using a jump-table. The example to the right side is slightly more efficient as the check for the lower boundary of the jump-table is not needed. \end_layout \end_deeper \begin_layout Itemize The number of case labels is not larger than supported by the target architectur e. \end_layout \begin_layout Itemize If the case labels are not in numerical sequence ('gaps' between cases) SDCC checks whether a jump table with additionally inserted dummy cases is still attractive. \end_layout \begin_layout Itemize If the starting number is not zero and a check for the lower boundary of the jump-table can thus be eliminated SDCC might insert dummy cases 0, ... . \end_layout \begin_layout Standard Switch statements which have large gaps in the numeric sequence or those that have too many case labels can be split into more than one switch statement for efficient code generation, e.g.: \end_layout \begin_layout Verse \family typewriter switch (i) { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 1: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 2: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 3: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 4: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 5: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 6: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 7: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 101: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 102: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 103: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 104: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 105: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 106: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 107: ... \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard If the above switch statement is broken down into two switch statements \end_layout \begin_layout Verse \family typewriter switch (i) { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 1: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 2: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 3: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 4: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 5: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 6: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 7: ... \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard and \end_layout \begin_layout Verse \family typewriter switch (i) { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 101: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 102: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 103: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 104: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 105: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 106: ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset case 107: ... \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard then both the switch statements will be implemented using jump-tables whereas the unmodified switch statement will not be. \end_layout \begin_layout Standard \begin_inset Note Note status collapsed \begin_layout Plain Layout There might be reasons which SDCC cannot know about to either favour or not favour jump tables. If the target system has to be as quick for the last switch case as for the first (pro jump table), or if the switch argument is known to be zero in the majority of the cases (contra jump table). \end_layout \end_inset \end_layout \begin_layout Subsection Bit-shifting Operations \begin_inset Index idx status collapsed \begin_layout Plain Layout Bit shifting \end_layout \end_inset . \end_layout \begin_layout Standard Bit shifting is one of the most frequently used operation in embedded programmin g. SDCC tries to implement bit-shift operations in the most efficient way possible, e.g.: \end_layout \begin_layout Verse \family typewriter unsigned char i; \begin_inset Newline newline \end_inset ... \begin_inset Newline newline \end_inset i >>= 4; \begin_inset Newline newline \end_inset ... \end_layout \begin_layout Standard generates the following code: \end_layout \begin_layout Verse \family typewriter mov \begin_inset space ~ \end_inset a,_i \begin_inset Newline newline \end_inset swap a \begin_inset Newline newline \end_inset anl \begin_inset space ~ \end_inset a,#0x0f \begin_inset Newline newline \end_inset mov \begin_inset space ~ \end_inset _i,a \end_layout \begin_layout Standard In general SDCC will never setup a loop if the shift count is known. Another example: \end_layout \begin_layout Verse \family typewriter unsigned int i; \begin_inset Newline newline \end_inset ... \begin_inset Newline newline \end_inset i >>= 9; \begin_inset Newline newline \end_inset ... \end_layout \begin_layout Standard will generate: \end_layout \begin_layout Verse \family typewriter mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,(_i + 1) \begin_inset Newline newline \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset (_i + 1),#0x00 \begin_inset Newline newline \end_inset clr \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset c \begin_inset Newline newline \end_inset rrc \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a \begin_inset Newline newline \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _i,a \end_layout \begin_layout Subsection Bit-rotation \begin_inset Index idx status collapsed \begin_layout Plain Layout Bit rotation \end_layout \end_inset \end_layout \begin_layout Standard A special case of the bit-shift operation is bit rotation \begin_inset Index idx status collapsed \begin_layout Plain Layout rotating bits \end_layout \end_inset , SDCC recognizes the following expression to be a left bit-rotation: \end_layout \begin_layout Verse \family typewriter \series bold unsigned \series default \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset char i; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* unsigned is needed for rotation */ \begin_inset Newline newline \end_inset ... \begin_inset Newline newline \end_inset i = ((i << 1) | (i >> 7)); \family default \begin_inset Newline newline \end_inset \family typewriter ... \end_layout \begin_layout Standard will generate the following code: \end_layout \begin_layout Verse \family typewriter mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,_i \begin_inset Newline newline \end_inset rl \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a \begin_inset Newline newline \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _i,a \end_layout \begin_layout Standard SDCC uses pattern matching on the parse tree to determine this operation.Variatio ns of this case will also be recognized as bit-rotation, i.e.: \end_layout \begin_layout Verse \family typewriter i = ((i >> 7) | (i << 1)); /* left-bit rotation */ \end_layout \begin_layout Subsection Nibble and Byte Swapping \end_layout \begin_layout Standard Other special cases of the bit-shift operations are nibble or byte swapping \begin_inset Index idx status collapsed \begin_layout Plain Layout swapping nibbles/bytes \end_layout \end_inset , SDCC recognizes the following expressions: \end_layout \begin_layout Verse \family typewriter \series bold unsigned \series default \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset char i; \begin_inset Newline newline \end_inset \series bold unsigned \series default \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset int j; \begin_inset Newline newline \end_inset ... \begin_inset Newline newline \end_inset i = ((i << 4) | (i >> 4)); \family default \begin_inset Newline newline \end_inset \family typewriter j = ((j << 8) | (j >> 8)); \end_layout \begin_layout Standard and generates a swap instruction for the nibble swapping \begin_inset Index idx status collapsed \begin_layout Plain Layout Nibble swapping \end_layout \end_inset or move instructions for the byte swapping \begin_inset Index idx status collapsed \begin_layout Plain Layout Byte swapping \end_layout \end_inset . The \begin_inset Quotes sld \end_inset j \begin_inset Quotes srd \end_inset example can be used to convert from little to big-endian or vice versa. If you want to change the endianness of a \emph on signed \emph default integer you have to cast to \family typewriter (unsigned int) \family default first. \end_layout \begin_layout Standard Note that SDCC stores numbers in little-endian \begin_inset Foot status collapsed \begin_layout Plain Layout Usually 8-bit processors don't care much about endianness. This is not the case for the standard 8051 which only has an instruction to increment its \emph on dptr \emph default \begin_inset Index idx status collapsed \begin_layout Plain Layout DPTR \end_layout \end_inset -datapointer so little-endian is the more efficient byte order. \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout little-endian \end_layout \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Endianness \end_layout \end_inset format (i.e. lowest order first) for most backends. However, the hc08, s08 and stm8 backends are big-endian. \end_layout \begin_layout Subsection Highest Order Bit \begin_inset Index idx status collapsed \begin_layout Plain Layout Highest Order Bit \end_layout \end_inset / Any Order Bit \begin_inset Index idx status collapsed \begin_layout Plain Layout Any Order Bit \end_layout \end_inset \end_layout \begin_layout Standard It is frequently required to obtain the highest order bit of an integral type (long, int, short or char types). Also obtaining any other order bit is not uncommon. SDCC recognizes the following expressions to yield the highest order bit and generates optimized code for it, e.g.: \end_layout \begin_layout Verse \family typewriter unsigned int gint; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset foo () { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset unsigned char hob1, aob1; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset bit hob2, hob3, aob2, aob3; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset hob1 = (gint >> 15) & 1; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset hob2 = (gint >> 15) & 1; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset hob3 = gint & 0x8000; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset aob1 = (gint >> 9) & 1; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset aob2 = (gint >> 8) & 1; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset aob3 = gint & 0x0800; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard will generate the following code: \end_layout \begin_layout Verse \family typewriter \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 61 ; \begin_inset space ~ \end_inset hob.c 7 \begin_inset Newline newline \end_inset 000A E5*01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 62 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,(_gint + 1) \begin_inset Newline newline \end_inset 000C 23 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 63 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset rl \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a \begin_inset Newline newline \end_inset 000D 54 01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 64 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset anl \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,#0x01 \begin_inset Newline newline \end_inset 000F F5*02 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 65 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _foo_hob1_1_1,a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 66 ; \begin_inset space ~ \end_inset hob.c 8 \begin_inset Newline newline \end_inset 0011 E5*01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 67 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,(_gint + 1) \begin_inset Newline newline \end_inset 0013 33 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 68 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset rlc \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a \begin_inset Newline newline \end_inset 0014 92*00 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 69 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _foo_hob2_1_1,c \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 66 ; \begin_inset space ~ \end_inset hob.c 9 \begin_inset Newline newline \end_inset 0016 E5*01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 67 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,(_gint + 1) \begin_inset Newline newline \end_inset 0018 33 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 68 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset rlc \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a \begin_inset Newline newline \end_inset 0019 92*01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 69 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _foo_hob3_1_1,c \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 70 ; \begin_inset space ~ \end_inset hob.c 10 \begin_inset Newline newline \end_inset 001B E5*01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 71 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,(_gint + 1) \begin_inset Newline newline \end_inset 001D 03 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 72 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset rr \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a \begin_inset Newline newline \end_inset 001E 54 01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 73 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset anl \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,#0x01 \begin_inset Newline newline \end_inset 0020 F5*03 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 74 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _foo_aob1_1_1,a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 75 ; \begin_inset space ~ \end_inset hob.c 11 \begin_inset Newline newline \end_inset 0022 E5*01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 76 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,(_gint + 1) \begin_inset Newline newline \end_inset 0024 13 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 77 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset rrc \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a \begin_inset Newline newline \end_inset 0025 92*02 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 78 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _foo_aob2_1_1,c \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 79 ; \begin_inset space ~ \end_inset hob.c 12 \begin_inset Newline newline \end_inset 0027 E5*01 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 80 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset a,(_gint + 1) \begin_inset Newline newline \end_inset 0029 A2 E3 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 81 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset c,acc[3] \begin_inset Newline newline \end_inset 002B 92*03 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 82 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _foo_aob3_1_1,c \end_layout \begin_layout Standard Other variations of these cases however will \emph on not \emph default be recognized. They are standard C expressions, so I heartily recommend these be the only way to get the highest order bit, (it is portable). Of course it will be recognized even if it is embedded in other expressions, e.g.: \end_layout \begin_layout Verse \family typewriter xyz = gint + ((gint >> 15) & 1); \end_layout \begin_layout Standard will still be recognized. \end_layout \begin_layout Subsection Higher Order Byte \begin_inset Index idx status collapsed \begin_layout Plain Layout Higher Order Byte \end_layout \end_inset / Higher Order Word \begin_inset Index idx status collapsed \begin_layout Plain Layout Higher Order Word \end_layout \end_inset \end_layout \begin_layout Standard It is also frequently required to obtain a higher order byte or word of a larger integral type (long, int or short types). SDCC recognizes the following expressions to yield the higher order byte or word and generates optimized code for it, e.g.: \end_layout \begin_layout Verse \family typewriter unsigned int gint; \begin_inset Newline newline \end_inset unsigned long int glong; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset foo () { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset unsigned char hob1, hob2; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset unsigned int how1, how2; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset hob1 = (gint >> 8) & 0xFF; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset hob2 = glong >> 24; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset how1 = (glong >> 16) & 0xFFFF; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset how2 = glong >> 8; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ... \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard will generate the following code: \end_layout \begin_layout Verse \family typewriter \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 91 ; \begin_inset space ~ \end_inset hob.c 15 \begin_inset Newline newline \end_inset 0037 85*01*06 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 92 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _foo_hob1_1_1,(_gint + 1) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 93 ; \begin_inset space ~ \end_inset hob.c 16 \begin_inset Newline newline \end_inset 003A 85*05*07 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 94 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _foo_hob2_1_1,(_glong + 3) \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 95 ; \begin_inset space ~ \end_inset hob.c 17 \begin_inset Newline newline \end_inset 003D 85*04*08 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 96 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _foo_how1_1_1,(_glong + 2) \begin_inset Newline newline \end_inset 0040 85*05*09 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 97 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset (_foo_how1_1_1 + 1),(_glong + 3) \begin_inset Newline newline \end_inset 0043 85*03*0A \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 98 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset _foo_how2_1_1,(_glong + 1) \begin_inset Newline newline \end_inset 0046 85*04*0B \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset 99 \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset (_foo_how2_1_1 + 1),(_glong + 2) \end_layout \begin_layout Standard Again, variations of these cases may \emph on not \emph default be recognized. They are standard C expressions, so I heartily recommend these be the only way to get the higher order byte/word, (it is portable). Of course it will be recognized even if it is embedded in other expressions, e.g.: \end_layout \begin_layout Verse \family typewriter xyz = gint + ((gint >> 8) & 0xFF); \end_layout \begin_layout Standard will still be recognized. \end_layout \begin_layout Subsection Placement of Bank-Selection Instructions \end_layout \begin_layout Standard For non-intrinsic named address spaces, SDCC will place the bank selection instructions optimally. For details see Philipp Klaus Krause, \begin_inset Quotes sld \end_inset Optimal Placement of Bank Selection Instructions in Polynomial Time \begin_inset Quotes srd \end_inset , Proceedings of the 16th International Workshop on Software and Compilers for Embedded Systems, M-SCOPES ’13, pp 23–30. Association for Computing Machinery, 2013. \end_layout \begin_layout Subsection Lifetime-Optimal Speculative Partial Redundancy Elimination \end_layout \begin_layout Standard SDCC has an implementation of lifetime-optimal speculative partial redundancy elimination based on tree-decompositions. \end_layout \begin_layout Subsection Register Allocation \begin_inset CommandInset label LatexCommand label name "subsec:Register-Allocation" \end_inset \begin_inset Index idx status open \begin_layout Plain Layout Register-Allocation \end_layout \end_inset \end_layout \begin_layout Standard SDCC currently has two register allocators. One of them is optimal when optimizing for code size. This register allocator is used by default on the hc08, s08, z80, z180, r2k, r3ka, gbz80 and stm8 ports. Even though it runs in polynomial time, it can be quite slow; therefore the \begin_inset Flex Code status open \begin_layout Plain Layout --max-allocs-per-node \end_layout \end_inset command line option can be used for a trade-off between compilation speed and quality of the generated code: Lower values result in faster compilation, higher values can result in better code being generated. \end_layout \begin_layout Standard It first creates a tree-decomposition of the control-flow graph, and then uses dynamic programming bottom-up along the tree-decomposition. Optimality is achieved through the use of a cost function, which gives cost for instructions under register assignments. The cost function is target-specific and has to be implemented for each port; in all current SDCC ports the cost function is integrated into code generation. \end_layout \begin_layout Standard For more details on how this register allocator works, see: Philipp Klaus Krause, \begin_inset Quotes sld \end_inset Optimal Register Allocation in Polynomial Time \begin_inset Quotes srd \end_inset , Compiler Construction - 22nd International Conference, CC 2013, Held as Part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2013. Proceedings, Lecture Notes in Computer Science, volume 7791, pp. 1-20. Springer, 2013. Also: Philipp Klaus Krause, \begin_inset Quotes sld \end_inset Bytewise Register Allocation \begin_inset Quotes srd \end_inset , Proceedings of the 18th International Workshop on Software and Compilers for Embedded Systems, SCOPES ’15, pp 22–27. Association for Computing Machinery, 2015. \end_layout \begin_layout Subsection Peephole Optimizer \begin_inset CommandInset label LatexCommand label name "subsec:Peephole-Optimizer" \end_inset \begin_inset Index idx status collapsed \begin_layout Plain Layout Peephole optimizer \end_layout \end_inset \end_layout \begin_layout Standard The compiler uses a rule based, pattern matching and re-writing mechanism for peep-hole optimization. It is inspired by \emph on copt \emph default a peep-hole optimizer by Christopher W. Fraser (cwfraser \begin_inset space ~ \end_inset @ \begin_inset space ~ \end_inset microsoft.com). A default set of rules are compiled into the compiler, additional rules may be added with the \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -peep-file \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -peep-file \end_layout \end_inset \emph default option. The rule language is best illustrated with examples. \end_layout \begin_layout Verse \family typewriter replace { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov %1,a \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,%1 \begin_inset Newline newline \end_inset } by { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov %1,a \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard The above rule will change the following assembly \begin_inset Index idx status collapsed \begin_layout Plain Layout Assembler routines \end_layout \end_inset sequence: \end_layout \begin_layout Verse \family typewriter mov r1,a \begin_inset Newline newline \end_inset mov a,r1 \end_layout \begin_layout Standard to \end_layout \begin_layout Verse \family typewriter mov r1,a \end_layout \begin_layout Standard Note: All occurrences of a \emph on %n \emph default (pattern variable) must denote the same string. With the above rule, the assembly sequence: \end_layout \begin_layout Verse \family typewriter mov r1,a \begin_inset Newline newline \end_inset mov a,r2 \end_layout \begin_layout Standard will remain unmodified. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Other special case optimizations may be added by the user (via \emph on - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -peep-file option \emph default ). E.g. some variants of the 8051 MCU \begin_inset Index idx status collapsed \begin_layout Plain Layout MCS51 variants \end_layout \end_inset allow only \family typewriter ajmp \family default and \family typewriter acall \family default . The following two rules will change all \family typewriter ljmp \family default and \family typewriter lcall \family default to \family typewriter ajmp \family default and \family typewriter acall \end_layout \begin_layout Verse \family typewriter replace { lcall %1 } by { acall %1 } \begin_inset Newline newline \end_inset replace { ljmp %1 } by { ajmp %1 } \end_layout \begin_layout Standard (NOTE: from version 2.7.3 on, you can use option - \emph on \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset \emph default -acall-ajmp \begin_inset Index idx status collapsed \begin_layout Plain Layout - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -acall-ajmp \end_layout \end_inset , which also takes care of aligning the interrupt vectors properly.) \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard The \emph on inline-assembler code \emph default is also passed through the peep hole optimizer, thus the peephole optimizer can also be used as an assembly level macro expander. The rules themselves are MCU dependent whereas the rule language infra-structur e is MCU independent. Peephole optimization rules for other MCU can be easily programmed using the rule language. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset The syntax for a rule is as follows: \end_layout \begin_layout Verse \family typewriter rule := replace [ restart ] '{' ' \backslash n' \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset '}' by '{' ' \backslash n' \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ' \backslash n' \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset '}' [if ] ' \backslash n' \end_layout \begin_layout Standard := assembly instruction (each instruction including labels must be on a separate line). \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset The optimizer will apply to the rules one by one from the top in the sequence of their appearance, it will terminate when all rules are exhausted. If the 'restart' option is specified, then the optimizer will start matching the rules again from the top, this option for a rule is expensive (performance) , it is intended to be used in situations where a transformation will trigger the same rule again. An example of this (not a good one, it has side effects) is the following rule: \end_layout \begin_layout Verse \family typewriter replace restart { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset pop %1 \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset push %1 } by { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ; nop \begin_inset Newline newline \end_inset } \end_layout \begin_layout Standard Note that the replace pattern cannot be a blank, but can be a comment line. Without the 'restart' option only the innermost 'pop' 'push' pair would be eliminated, i.e.: \end_layout \begin_layout Verse \family typewriter pop ar1 \begin_inset Newline newline \end_inset pop ar2 \begin_inset Newline newline \end_inset push ar2 \begin_inset Newline newline \end_inset push ar1 \end_layout \begin_layout Standard would result in: \end_layout \begin_layout Verse \family typewriter pop ar1 \begin_inset Newline newline \end_inset ; nop \begin_inset Newline newline \end_inset push ar1 \end_layout \begin_layout Standard \emph on with \emph default the restart option the rule will be applied again to the resulting code and then all the pop-push pairs will be eliminated to yield: \end_layout \begin_layout Verse \family typewriter ; nop \begin_inset Newline newline \end_inset ; nop \end_layout \begin_layout Standard A conditional function can be attached to a rule. Attaching rules are somewhat more involved, let's illustrate this with an example. \end_layout \begin_layout Verse \family typewriter replace { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ljmp %5 \begin_inset Newline newline \end_inset %2: \begin_inset Newline newline \end_inset } by { \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sjmp %5 \begin_inset Newline newline \end_inset %2: \begin_inset Newline newline \end_inset } if labelInRange \end_layout \begin_layout Standard The optimizer does a look-up of a function name table defined in function \emph on callFuncByName \emph default in the source file SDCCpeeph.c, with the name \emph on labelInRange \emph default . If it finds a corresponding entry the function is called. Note there can be no parameters specified for some of these functions, in this case the use of \emph on %5 \emph default is crucial, since the function \emph on labelInRange \emph default expects to find the label in that particular variable (the hash table containin g the variable bindings is passed as a parameter). If you want to code more such functions, take a close look at the function labelInRange and the calling mechanism in source file SDCCpeeph.c. Currently implemented are \emph on labelInRange, labelRefCount, labelRefCountChange, labelIsReturnOnly, xramMovcOpt ion, portIsDS390, 24bitMode, notVolatile \emph default . \emph on notUsed, notSame, operandsNotRelated, labelJTInRange, canAssign, optimizeReturn, notUsedFrom, labelIsReturnOnly, operandsLiteral, labelIsUncondJump, deadMove, useAcallAjmp \emph default and \emph on okToRemoveSLOC. \end_layout \begin_layout Standard This whole thing is a little kludgy, but maybe some day SDCC will have some better means. If you are looking at the \family typewriter peeph*.def \family default files, you will see the default rules that are compiled into the compiler, you can add your own rules in the default set there if you get tired of specifying the - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -peep-file option. \end_layout \begin_layout Section Cyclomatic Complexity \begin_inset Index idx status collapsed \begin_layout Plain Layout Cyclomatic complexity \end_layout \end_inset \end_layout \begin_layout Standard Cyclomatic complexity of a function is defined as the number of independent paths the program can take during execution of the function. This is an important number since it defines the number test cases you have to generate to validate the function. The accepted industry standard for complexity number is 10, if the cyclomatic complexity reported by SDCC exceeds 10 you should think about simplification of the function logic. Note that the complexity level is not related to the number of lines of code in a function. Large functions can have low complexity, and small functions can have large complexity levels. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset SDCC uses the following formula to compute the complexity: \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard complexity = (number of edges in control flow graph) - (number of nodes in control flow graph) + 2; \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Having said that the industry standard is 10, you should be aware that in some cases it be may unavoidable to have a complexity level of less than 10. For example if you have switch statement with more than 10 case labels, each case label adds one to the complexity level. The complexity level is by no means an absolute measure of the algorithmic complexity of the function, it does however provide a good starting point for which functions you might look at for further optimization. \end_layout \begin_layout Section Retargetting for other Processors \end_layout \begin_layout Standard The issues for retargetting the compiler are far too numerous to be covered by this document. What follows is a brief description of each of the phases of the compiler and its MCU dependency. \end_layout \begin_layout Itemize Parsing the source and building the annotated parse tree. This phase is largely MCU independent (except for the language extensions). Syntax & semantic checks are also done in this phase, along with some initial optimizations like back patching labels and the pattern matching optimizations like bit-rotation etc. \end_layout \begin_layout Itemize The second phase involves generating an intermediate code which can be easy manipulated during the later phases. This phase is entirely MCU independent. The intermediate code generation assumes the target machine has unlimited number of registers, and designates them with the name iTemp. The compiler can be made to dump a human readable form of the code generated by using the - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset -dumpraw option. \end_layout \begin_layout Itemize This phase does the bulk of the standard optimizations and is also MCU independe nt. This phase can be broken down into several sub-phases: \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Break down intermediate code (iCode) into basic blocks. \begin_inset Newline newline \end_inset Do control flow & data flow analysis on the basic blocks. \begin_inset Newline newline \end_inset Do local common subexpression elimination, then global subexpression elimination \begin_inset Newline newline \end_inset Dead code elimination \begin_inset Newline newline \end_inset Loop optimizations \begin_inset Newline newline \end_inset If loop optimizations caused any changes then do 'global subexpression eliminati on' and 'dead code elimination' again. \end_layout \begin_layout Itemize This phase determines the live-ranges; by live range I mean those iTemp variables defined by the compiler that still survive after all the optimization s. Live range analysis \begin_inset Index idx status collapsed \begin_layout Plain Layout Live range analysis \end_layout \end_inset is essential for register allocation, since these computation determines which of these iTemps will be assigned to registers, and for how long. \end_layout \begin_layout Itemize Phase five is register allocation. For new ports register allocator described above in \begin_inset CommandInset ref LatexCommand ref reference "subsec:Register-Allocation" \end_inset should be used in most cases, since it can result in substantially better code. In the old register allocator, there are two parts to register allocation. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset The first part I call 'register packing' (for lack of a better term). In this case several MCU specific expression folding is done to reduce register pressure. \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset The second part is more MCU independent and deals with allocating registers to the remaining live ranges. A lot of MCU specific code does creep into this phase because of the limited number of index registers available in the 8051. \end_layout \begin_layout Itemize The Code generation phase is (unhappily), entirely MCU dependent and very little (if any at all) of this code can be reused for other MCU. However the scheme for allocating a homogenized assembler operand for each iCode operand may be reused. \end_layout \begin_layout Itemize As mentioned in the optimization section the peep-hole optimizer is rule based system, which can reprogrammed for other MCUs. \end_layout \begin_layout Standard More information is available on SDCC Wiki \begin_inset Index idx status collapsed \begin_layout Plain Layout wiki \end_layout \end_inset (preliminary link \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/wiki/index.php/SDCC_internals_and_porting \end_layout \end_inset ) and in the thread \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/mailarchive/message.php?msg_id=13954144 \end_layout \end_inset . \end_layout \begin_layout Chapter Compiler internals \begin_inset Index idx status collapsed \begin_layout Plain Layout Compiler internals \end_layout \end_inset \end_layout \begin_layout Section The anatomy of the compiler \begin_inset CommandInset label LatexCommand label name "subsec:The-anatomy-of" \end_inset \end_layout \begin_layout Standard \shape italic This is an excerpt from an article published in Circuit Cellar Magazine in \shape default \series bold \shape italic August 2000 \series default . It's outdated (the compiler is much more efficient now and user/developer friendly), but pretty well exposes the guts of it all. \shape default \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset The current version of SDCC can generate code for Intel 8051 and Z80 MCU. It is fairly easy to retarget for other 8-bit MCU. Here we take a look at some of the internals of the compiler. \end_layout \begin_layout Paragraph* Parsing \begin_inset Index idx status collapsed \begin_layout Plain Layout Parsing \end_layout \end_inset \end_layout \begin_layout Standard Parsing the input source file and creating an AST (Annotated Syntax Tree \begin_inset Index idx status collapsed \begin_layout Plain Layout Annotated syntax tree \end_layout \end_inset ). This phase also involves propagating types (annotating each node of the parse tree with type information) and semantic analysis. There are some MCU specific parsing rules. For example the intrinsic named address spaces are MCU specific: While there may be an __xdata intrinsic named address space for 8051 there none for z80. SDCC has MCU specific intrinsic named address spacess, i.e. __xdata will be treated as a named address space when parsing 8051 C code but will be treated as a C identifier when parsing z80 code. \end_layout \begin_layout Paragraph* Generating iCode \begin_inset Index idx status collapsed \begin_layout Plain Layout iCode \end_layout \end_inset \end_layout \begin_layout Standard Intermediate code generation. In this phase the AST is broken down into three-operand form (iCode). These three operand forms are represented as doubly linked lists. ICode is the term given to the intermediate form generated by the compiler. ICode example section shows some examples of iCode generated for some simple C source functions. \end_layout \begin_layout Paragraph* Optimizations \begin_inset Index idx status collapsed \begin_layout Plain Layout Optimizations \end_layout \end_inset . \end_layout \begin_layout Standard Bulk of the target independent optimizations is performed in this phase. The optimizations include constant propagation, common sub-expression eliminati on, loop invariant code movement, strength reduction of loop induction variables and dead-code elimination. \end_layout \begin_layout Paragraph* Live range analysis \begin_inset Index idx status collapsed \begin_layout Plain Layout Live range analysis \end_layout \end_inset \end_layout \begin_layout Standard During intermediate code generation phase, the compiler assumes the target machine has infinite number of registers and generates a lot of temporary variables. The live range computation determines the lifetime of each of these compiler-ge nerated temporaries. A picture speaks a thousand words. ICode example sections show the live range annotations for each of the operand. It is important to note here, each iCode is assigned a number in the order of its execution in the function. The live ranges are computed in terms of these numbers. The from number is the number of the iCode which first defines the operand and the to number signifies the iCode which uses this operand last. \end_layout \begin_layout Paragraph* Register Allocation \begin_inset Index idx status collapsed \begin_layout Plain Layout Register allocation \end_layout \end_inset \end_layout \begin_layout Standard The register allocation determines the type and number of registers needed by each operand. In most MCUs only a few registers can be used for indirect addressing. In case of 8051 for example the registers R0 & R1 can be used to indirectly address the internal ram and DPTR to indirectly address the external ram. The compiler will try to allocate the appropriate register to pointer variables if it can. ICode example section shows the operands annotated with the registers assigned to them. The compiler will try to keep operands in registers as much as possible; there are several schemes the compiler uses to do achieve this. When the compiler runs out of registers the compiler will check to see if there are any live operands which is not used or defined in the current basic block being processed, if there are any found then it will push that operand and use the registers in this block, the operand will then be popped at the end of the basic block. \end_layout \begin_layout Standard There are other MCU specific considerations in this phase. Some MCUs have an accumulator; very short-lived operands could be assigned to the accumulator instead of a general-purpose register. \end_layout \begin_layout Paragraph* Code generation \end_layout \begin_layout Standard Figure II gives a table of iCode \begin_inset Index idx status collapsed \begin_layout Plain Layout iCode \end_layout \end_inset operations supported by the compiler. The code generation involves translating these operations into corresponding assembly code for the processor. This sounds overly simple but that is the essence of code generation. Some of the iCode operations are generated on a MCU specific manner for example, the z80 port does not use registers to pass parameters so the SEND and RECV iCode operations will not be generated, and it also does not support JUMPTABLES. \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard \size footnotesize Figure II \begin_inset Tabular \begin_inset Text \begin_layout Plain Layout \series bold iCode \series default \begin_inset Index idx status collapsed \begin_layout Plain Layout iCode \end_layout \end_inset \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold Operands \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold Description \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \series bold C Equivalent \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize '!' \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize NOT operation \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = ! IC_LEFT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize '~' \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Bitwise complement of \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = ~IC_LEFT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize RRC \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Rotate right with carry \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = (IC_LEFT << 1) | (IC_LEFT >> (sizeof(IC_LEFT)*8-1)); \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize RLC \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Rotate left with carry \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = (IC_LEFT << (sizeof(LC_LEFT)*8-1) ) | (IC_LEFT >> 1); \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize GETHBIT \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Get the highest order bit of IC_LEFT \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = (IC_LEFT >> (sizeof(IC_LEFT)*8 -1)); \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize UNARYMINUS \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Unary minus \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = - IC_LEFT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IPUSH \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Push the operand into stack \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize NONE \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IPOP \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Pop the operand from the stack \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize NONE \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize CALL \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Call the function represented by IC_LEFT \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT(); \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize PCALL \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Call via function pointer \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = (*IC_LEFT)(); \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize RETURN \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Return the value in operand IC_LEFT \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize return IC_LEFT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize LABEL \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LABEL() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Label \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LABEL: \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize GOTO \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LABEL() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Goto label \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize goto IC_LABEL(); \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize '+' \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Addition \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT + IC_RIGHT \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize '-' \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Subtraction \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT - IC_RIGHT \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize '*' \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Multiplication \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT * IC_RIGHT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize '/' \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Division \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT / IC_RIGHT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize '%' \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Modulus \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT % IC_RIGHT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize '<' \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Less than \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT < IC_RIGHT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize '>' \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Greater than \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT > IC_RIGHT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize EQ_OP \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Equal to \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT == IC_RIGHT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize AND_OP \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Logical and operation \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT && IC_RIGHT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize OR_OP \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Logical or operation \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT || IC_RIGHT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize '^' \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Exclusive OR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT ^ IC_RIGHT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize '|' \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Bitwise OR \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT | IC_RIGHT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize BITWISEAND \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Bitwise AND \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT & IC_RIGHT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize LEFT_OP \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Left shift \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT << IC_RIGHT \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize RIGHT_OP \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Right shift \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_LEFT >> IC_RIGHT \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize GET_VALUE_ \begin_inset Newline newline \end_inset AT_ ADDRESS \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Indirect fetch \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = (*IC_LEFT); \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize POINTER_SET \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Indirect set \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize (*IC_RESULT) = IC_RIGHT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize '=' \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RIGHT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Assignment \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = IC_RIGHT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IFX \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_COND IC_TRUE IC_LABEL \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Conditional jump. If true label is present then jump to true label if condition is true else jump to false label if condition is false \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize if (IC_COND) goto IC_TRUE; \begin_inset Newline newline \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset Or \begin_inset Newline newline \end_inset If (!IC_COND) goto IC_FALSE; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize ADDRESS_OF \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Address of \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = &IC_LEFT(); \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize JUMPTABLE \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_JTCOND IC_JTLABELS \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Jump to list of labels depending on the value of JTCOND \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Switch statement \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize CAST \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RIGHT() IC_LEFT() IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize Cast types \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT = (typeof IC_LEFT) IC_RIGHT; \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize SEND \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_LEFT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize This is used for passing parameters in registers; \begin_inset Newline newline \end_inset move IC_LEFT to the next available parameter register. \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize None \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize RECV \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize IC_RESULT() \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize This is used for receiving parameters passed in registers; \begin_inset Newline newline \end_inset Move the values in the next parameter register to IC_RESULT \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \size footnotesize None \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \shape slanted \size footnotesize (some more have been added) \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \end_layout \end_inset \begin_inset Text \begin_layout Plain Layout \shape slanted \size footnotesize see f.e. \shape default \family typewriter \shape slanted gen51Code() \family default \shape default \shape slanted in \shape default \family typewriter \shape slanted src/mcs51/gen.c \end_layout \end_inset \end_inset \end_layout \begin_layout Standard \begin_inset Note Note status collapsed \begin_layout Plain Layout In the original article Figure II was announced to be downloadable on \shape italic Circuit Cellar \shape default 's web site. ftp://ftp.circuitcellar.com/pub/Circuit_Cellar/2000/121/dutta.ZIP \end_layout \end_inset \end_layout \begin_layout Paragraph* ICode Example \begin_inset Index idx status collapsed \begin_layout Plain Layout iCode \end_layout \end_inset \end_layout \begin_layout Standard This section shows some details of iCode. The example C code does not do anything useful; it is used as an example to illustrate the intermediate code generated by the compiler. \end_layout \begin_layout Verse \family typewriter 1. \begin_inset space ~ \end_inset __xdata int * p; \begin_inset Newline newline \end_inset 2. \begin_inset space ~ \end_inset int gint; \begin_inset Newline newline \end_inset 3. \begin_inset space ~ \end_inset /* This function does nothing useful. It is used \begin_inset Newline newline \end_inset 4. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset for the purpose of explaining iCode */ \begin_inset Newline newline \end_inset 5. \begin_inset space ~ \end_inset short function (__data int *x) \begin_inset Newline newline \end_inset 6. \begin_inset space ~ \end_inset { \begin_inset Newline newline \end_inset 7. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset short i=10; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* dead initialization eliminated */ \begin_inset Newline newline \end_inset 8. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset short sum=10; /* dead initialization eliminated */ \begin_inset Newline newline \end_inset 9. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset short mul; \begin_inset Newline newline \end_inset 10. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset int j ; \begin_inset Newline newline \end_inset 11. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset while (*x) *x++ = *p++; \begin_inset Newline newline \end_inset 12. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sum = 0 ; \begin_inset Newline newline \end_inset 13. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mul = 0; \begin_inset Newline newline \end_inset 14. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* compiler detects i,j to be induction variables */ \begin_inset Newline newline \end_inset 15. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset for (i = 0, j = 10 ; i < 10 ; i++, j \family default - \begin_inset ERT status collapsed \begin_layout Plain Layout \backslash / \end_layout \end_inset - \family typewriter ) { \begin_inset Newline newline \end_inset 16. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sum += i; \begin_inset Newline newline \end_inset 17. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mul += i * 3; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* this multiplication remains */ \begin_inset Newline newline \end_inset 18. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset gint += j * 3; \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset /* this multiplication changed to addition */ \begin_inset Newline newline \end_inset 19. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset } \begin_inset Newline newline \end_inset 20. \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset return sum+mul; \begin_inset Newline newline \end_inset 21. \begin_inset space ~ \end_inset } \end_layout \begin_layout Standard In addition to the operands each iCode contains information about the filename and line it corresponds to in the source file. The first field in the listing should be interpreted as follows: \begin_inset Newline newline \end_inset \shape italic \size footnotesize Filename(linenumber: iCode Execution sequence number : ICode hash table key : loop depth of the iCode). \shape default \size default \begin_inset Newline newline \end_inset Then follows the human readable form of the ICode operation. Each operand of this triplet form can be of three basic types a) compiler generated temporary b) user defined variable c) a constant value. Note that local variables and parameters are replaced by compiler generated temporaries. Live ranges \begin_inset Index idx status collapsed \begin_layout Plain Layout Live range analysis \end_layout \end_inset are computed only for temporaries (i.e. live ranges are not computed for global variables). Registers \begin_inset Index idx status collapsed \begin_layout Plain Layout Register allocation \end_layout \end_inset are allocated for temporaries only. Operands are formatted in the following manner: \begin_inset Newline newline \end_inset \shape italic \size footnotesize Operand Name [lr live-from : live-to ] { type information } [ registers allocated ]. \shape default \size default \begin_inset Newline newline \end_inset As mentioned earlier the live ranges are computed in terms of the execution sequence number of the iCodes, for example \begin_inset Newline newline \end_inset the iTemp0 is live from (i.e. first defined in iCode with execution sequence number 3, and is last used in the iCode with sequence number 5). For induction variables such as iTemp21 the live range computation extends the lifetime from the start to the end of the loop. \begin_inset Newline newline \end_inset The register allocator used the live range information to allocate registers, the same registers may be used for different temporaries if their live ranges do not overlap, for example r0 is allocated to both iTemp6 and to iTemp17 since their live ranges do not overlap. In addition the allocator also takes into consideration the type and usage of a temporary, for example itemp6 is a pointer to near space and is used as to fetch data from (i.e. used in GET_VALUE_AT_ADDRESS) so it is allocated a pointer register (r0). Some short lived temporaries are allocated to special registers which have meaning to the code generator e.g. iTemp13 is allocated to a pseudo register CC which tells the back end that the temporary is used only for a conditional jump the code generation makes use of this information to optimize a compare and jump ICode. \begin_inset Newline newline \end_inset There are several loop optimizations \begin_inset Index idx status collapsed \begin_layout Plain Layout Loop optimization \end_layout \end_inset performed by the compiler. It can detect induction variables iTemp21(i) and iTemp23(j). Also note the compiler does selective strength reduction \begin_inset Index idx status collapsed \begin_layout Plain Layout Strength reduction \end_layout \end_inset , i.e. the multiplication of an induction variable in line 18 (gint = j * 3) is changed to addition, a new temporary iTemp17 is allocated and assigned a initial value, a constant 3 is then added for each iteration of the loop. The compiler does not change the multiplication \begin_inset Index idx status collapsed \begin_layout Plain Layout Multiplication \end_layout \end_inset in line 17 however since the processor does support an 8 * 8 bit multiplication. \begin_inset Newline newline \end_inset Note the dead code elimination \begin_inset Index idx status collapsed \begin_layout Plain Layout Dead-code elimination \end_layout \end_inset optimization eliminated the dead assignments in line 7 & 8 to I and sum respectively. \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard \size footnotesize Sample.c (5:1:0:0) _entry($9) : \end_layout \begin_layout Standard \size footnotesize Sample.c(5:2:1:0) proc _function [lr0:0]{function short} \end_layout \begin_layout Standard \size footnotesize Sample.c(11:3:2:0) iTemp0 [lr3:5]{_near * int}[r2] = recv \end_layout \begin_layout Standard \size footnotesize Sample.c(11:4:53:0) preHeaderLbl0($11) : \end_layout \begin_layout Standard \size footnotesize Sample.c(11:5:55:0) iTemp6 [lr5:16]{_near * int}[r0] := iTemp0 [lr3:5]{_near * int}[r2] \end_layout \begin_layout Standard \size footnotesize Sample.c(11:6:5:1) _whilecontinue_0($1) : \end_layout \begin_layout Standard \size footnotesize Sample.c(11:7:7:1) iTemp4 [lr7:8]{int}[r2 r3] = @[iTemp6 [lr5:16]{_near * int}[r0]] \end_layout \begin_layout Standard \size footnotesize Sample.c(11:8:8:1) if iTemp4 [lr7:8]{int}[r2 r3] == 0 goto _whilebreak_0($3) \end_layout \begin_layout Standard \size footnotesize Sample.c(11:9:14:1) iTemp7 [lr9:13]{_far * int}[DPTR] := _p [lr0:0]{_far * int} \end_layout \begin_layout Standard \size footnotesize Sample.c(11:10:15:1) _p [lr0:0]{_far * int} = _p [lr0:0]{_far * int} + 0x2 {short} \end_layout \begin_layout Standard \size footnotesize Sample.c(11:13:18:1) iTemp10 [lr13:14]{int}[r2 r3] = @[iTemp7 [lr9:13]{_far * int}[DPTR]] \end_layout \begin_layout Standard \size footnotesize Sample.c(11:14:19:1) *(iTemp6 [lr5:16]{_near * int}[r0]) := iTemp10 [lr13:14]{int }[r2 r3] \end_layout \begin_layout Standard \size footnotesize Sample.c(11:15:12:1) iTemp6 [lr5:16]{_near * int}[r0] = iTemp6 [lr5:16]{_near * int}[r0] + 0x2 {short} \end_layout \begin_layout Standard \size footnotesize Sample.c(11:16:20:1) goto _whilecontinue_0($1) \end_layout \begin_layout Standard \size footnotesize Sample.c(11:17:21:0)_whilebreak_0($3) : \end_layout \begin_layout Standard \size footnotesize Sample.c(12:18:22:0) iTemp2 [lr18:40]{short}[r2] := 0x0 {short} \end_layout \begin_layout Standard \size footnotesize Sample.c(13:19:23:0) iTemp11 [lr19:40]{short}[r3] := 0x0 {short} \end_layout \begin_layout Standard \size footnotesize Sample.c(15:20:54:0)preHeaderLbl1($13) : \end_layout \begin_layout Standard \size footnotesize Sample.c(15:21:56:0) iTemp21 [lr21:38]{short}[r4] := 0x0 {short} \end_layout \begin_layout Standard \size footnotesize Sample.c(15:22:57:0) iTemp23 [lr22:38]{int}[r5 r6] := 0xa {int} \end_layout \begin_layout Standard \size footnotesize Sample.c(15:23:58:0) iTemp17 [lr23:38]{int}[r7 r0] := 0x1e {int} \end_layout \begin_layout Standard \size footnotesize Sample.c(15:24:26:1)_forcond_0($4) : \end_layout \begin_layout Standard \size footnotesize Sample.c(15:25:27:1) iTemp13 [lr25:26]{char}[CC] = iTemp21 [lr21:38]{short}[r4] < 0xa {short} \end_layout \begin_layout Standard \size footnotesize Sample.c(15:26:28:1) if iTemp13 [lr25:26]{char}[CC] == 0 goto _forbreak_0($7) \end_layout \begin_layout Standard \size footnotesize Sample.c(16:27:31:1) iTemp2 [lr18:40]{short}[r2] = iTemp2 [lr18:40]{short}[r2] + ITemp21 [lr21:38]{short}[r4] \end_layout \begin_layout Standard \size footnotesize Sample.c(17:29:33:1) iTemp15 [lr29:30]{short}[r1] = iTemp21 [lr21:38]{short}[r4] * 0x3 {short} \end_layout \begin_layout Standard \size footnotesize Sample.c(17:30:34:1) iTemp11 [lr19:40]{short}[r3] = iTemp11 [lr19:40]{short}[r3] + iTemp15 [lr29:30]{short}[r1] \end_layout \begin_layout Standard \size footnotesize Sample.c(18:32:36:1:1) iTemp17 [lr23:38]{int}[r7 r0]= iTemp17 [lr23:38]{int}[r7 r0]- 0x3 {short} \end_layout \begin_layout Standard \size footnotesize Sample.c(18:33:37:1) _gint [lr0:0]{int} = _gint [lr0:0]{int} + iTemp17 [lr23:38]{ int}[r7 r0] \end_layout \begin_layout Standard \size footnotesize Sample.c(15:36:42:1) iTemp21 [lr21:38]{short}[r4] = iTemp21 [lr21:38]{short}[r4] + 0x1 {short} \end_layout \begin_layout Standard \size footnotesize Sample.c(15:37:45:1) iTemp23 [lr22:38]{int}[r5 r6]= iTemp23 [lr22:38]{int}[r5 r6]- 0x1 {short} \end_layout \begin_layout Standard \size footnotesize Sample.c(19:38:47:1) goto _forcond_0($4) \end_layout \begin_layout Standard \size footnotesize Sample.c(19:39:48:0)_forbreak_0($7) : \end_layout \begin_layout Standard \size footnotesize Sample.c(20:40:49:0) iTemp24 [lr40:41]{short}[DPTR] = iTemp2 [lr18:40]{short}[r2] + ITemp11 [lr19:40]{short}[r3] \end_layout \begin_layout Standard \size footnotesize Sample.c(20:41:50:0) ret iTemp24 [lr40:41]{short} \end_layout \begin_layout Standard \size footnotesize Sample.c(20:42:51:0)_return($8) : \end_layout \begin_layout Standard \size footnotesize Sample.c(20:43:52:0) eproc _function [lr0:0]{ ia0 re0 rm0}{function short} \size default \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset Finally the code generated for this function: \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard \size footnotesize .area DSEG (DATA) \end_layout \begin_layout Standard \size footnotesize _p:: \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .ds 2 \end_layout \begin_layout Standard \size footnotesize _gint:: \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset .ds 2 \end_layout \begin_layout Standard \size footnotesize ; sample.c 5 \end_layout \begin_layout Standard \size footnotesize ; ———————————————- \end_layout \begin_layout Standard \size footnotesize ; function function \end_layout \begin_layout Standard \size footnotesize ; ———————————————- \end_layout \begin_layout Standard \size footnotesize _function: \end_layout \begin_layout Standard \size footnotesize ; iTemp0 [lr3:5]{_near * int}[r2] = recv \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r2,dpl \end_layout \begin_layout Standard \size footnotesize ; iTemp6 [lr5:16]{_near * int}[r0] := iTemp0 [lr3:5]{_near * int}[r2] \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov ar0,r2 \end_layout \begin_layout Standard \size footnotesize ;_whilecontinue_0($1) : \end_layout \begin_layout Standard \size footnotesize 00101$: \end_layout \begin_layout Standard \size footnotesize ; iTemp4 [lr7:8]{int}[r2 r3] = @[iTemp6 [lr5:16]{_near * int}[r0]] \end_layout \begin_layout Standard \size footnotesize ; if iTemp4 [lr7:8]{int}[r2 r3] == 0 goto _whilebreak_0($3) \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov ar2,@r0 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc r0 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov ar3,@r0 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dec r0 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,r2 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset orl a,r3 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset jz 00103$ \end_layout \begin_layout Standard \size footnotesize 00114$: \end_layout \begin_layout Standard \size footnotesize ; iTemp7 [lr9:13]{_far * int}[DPTR] := _p [lr0:0]{_far * int} \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov dpl,_p \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov dph,(_p + 1) \end_layout \begin_layout Standard \size footnotesize ; _p [lr0:0]{_far * int} = _p [lr0:0]{_far * int} + 0x2 {short} \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,#0x02 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset add a,_p \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov _p,a \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset clr a \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset addc a,(_p + 1) \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov (_p + 1),a \end_layout \begin_layout Standard \size footnotesize ; iTemp10 [lr13:14]{int}[r2 r3] = @[iTemp7 [lr9:13]{_far * int}[DPTR]] \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset movx a,@dptr \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r2,a \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc dptr \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset movx a,@dptr \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r3,a \end_layout \begin_layout Standard \size footnotesize ; *(iTemp6 [lr5:16]{_near * int}[r0]) := iTemp10 [lr13:14]{int}[r2 r3] \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov @r0,ar2 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc r0 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov @r0,ar3 \end_layout \begin_layout Standard \size footnotesize ; iTemp6 [lr5:16]{_near * int}[r0] = \end_layout \begin_layout Standard \size footnotesize ; iTemp6 [lr5:16]{_near * int}[r0] + \end_layout \begin_layout Standard \size footnotesize ; 0x2 {short} \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc r0 \end_layout \begin_layout Standard \size footnotesize ; goto _whilecontinue_0($1) \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sjmp 00101$ \end_layout \begin_layout Standard \size footnotesize ; _whilebreak_0($3) : \end_layout \begin_layout Standard \size footnotesize 00103$: \end_layout \begin_layout Standard \size footnotesize ; iTemp2 [lr18:40]{short}[r2] := 0x0 {short} \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r2,#0x00 \end_layout \begin_layout Standard \size footnotesize ; iTemp11 [lr19:40]{short}[r3] := 0x0 {short} \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r3,#0x00 \end_layout \begin_layout Standard \size footnotesize ; iTemp21 [lr21:38]{short}[r4] := 0x0 {short} \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r4,#0x00 \end_layout \begin_layout Standard \size footnotesize ; iTemp23 [lr22:38]{int}[r5 r6] := 0xa {int} \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r5,#0x0A \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r6,#0x00 \end_layout \begin_layout Standard \size footnotesize ; iTemp17 [lr23:38]{int}[r7 r0] := 0x1e {int} \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r7,#0x1E \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r0,#0x00 \end_layout \begin_layout Standard \size footnotesize ; _forcond_0($4) : \end_layout \begin_layout Standard \size footnotesize 00104$: \end_layout \begin_layout Standard \size footnotesize ; iTemp13 [lr25:26]{char}[CC] = iTemp21 [lr21:38]{short}[r4] < 0xa {short} \end_layout \begin_layout Standard \size footnotesize ; if iTemp13 [lr25:26]{char}[CC] == 0 goto _forbreak_0($7) \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset clr c \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,r4 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset xrl a,#0x80 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset subb a,#0x8a \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset jnc 00107$ \end_layout \begin_layout Standard \size footnotesize 00115$: \end_layout \begin_layout Standard \size footnotesize ; iTemp2 [lr18:40]{short}[r2] = iTemp2 [lr18:40]{short}[r2] + \end_layout \begin_layout Standard \size footnotesize ; iTemp21 [lr21:38]{short}[r4] \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,r4 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset add a,r2 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r2,a \end_layout \begin_layout Standard \size footnotesize ; iTemp15 [lr29:30]{short}[r1] = iTemp21 [lr21:38]{short}[r4] * 0x3 {short} \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov b,#0x03 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,r4 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mul ab \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r1,a \end_layout \begin_layout Standard \size footnotesize ; iTemp11 [lr19:40]{short}[r3] = iTemp11 [lr19:40]{short}[r3] + \end_layout \begin_layout Standard \size footnotesize ; iTemp15 [lr29:30]{short}[r1] \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset add a,r3 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r3,a \end_layout \begin_layout Standard \size footnotesize ; iTemp17 [lr23:38]{int}[r7 r0]= iTemp17 [lr23:38]{int}[r7 r0]- 0x3 {short} \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,r7 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset add a,#0xfd \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r7,a \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,r0 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset addc a,#0xff \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov r0,a \end_layout \begin_layout Standard \size footnotesize ; _gint [lr0:0]{int} = _gint [lr0:0]{int} + iTemp17 [lr23:38]{int}[r7 r0] \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,r7 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset add a,_gint \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov _gint,a \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,r0 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset addc a,(_gint + 1) \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov (_gint + 1),a \end_layout \begin_layout Standard \size footnotesize ; iTemp21 [lr21:38]{short}[r4] = iTemp21 [lr21:38]{short}[r4] + 0x1 {short} \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset inc r4 \end_layout \begin_layout Standard \size footnotesize ; iTemp23 [lr22:38]{int}[r5 r6]= iTemp23 [lr22:38]{int}[r5 r6]- 0x1 {short} \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dec r5 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset cjne r5,#0xff,00104$ \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset dec r6 \end_layout \begin_layout Standard \size footnotesize ; goto _forcond_0($4) \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset sjmp 00104$ \end_layout \begin_layout Standard \size footnotesize ; _forbreak_0($7) : \end_layout \begin_layout Standard \size footnotesize 00107$: \end_layout \begin_layout Standard \size footnotesize ; ret iTemp24 [lr40:41]{short} \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov a,r3 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset add a,r2 \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset mov dpl,a \end_layout \begin_layout Standard \size footnotesize ; _return($8) : \end_layout \begin_layout Standard \size footnotesize 00108$: \end_layout \begin_layout Standard \size footnotesize \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset ret \begin_inset Newline newline \end_inset \end_layout \begin_layout Section A few words about basic block successors, predecessors and dominators \end_layout \begin_layout Standard Successors are basic blocks \begin_inset Index idx status collapsed \begin_layout Plain Layout Basic blocks \end_layout \end_inset that might execute after this basic block. \begin_inset Newline newline \end_inset Predecessors are basic blocks that might execute before reaching this basic block. \begin_inset Newline newline \end_inset Dominators are basic blocks that WILL execute before reaching this basic block. \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard [basic block 1] \end_layout \begin_layout Standard if (something) \end_layout \begin_layout Standard \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset [basic block 2] \end_layout \begin_layout Standard else \end_layout \begin_layout Standard \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset \begin_inset space ~ \end_inset [basic block 3] \end_layout \begin_layout Standard [basic block 4] \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard a) succList of [BB2] = [BB4], of [BB3] = [BB4], of [BB1] = [BB2,BB3] \end_layout \begin_layout Standard b) predList of [BB2] = [BB1], of [BB3] = [BB1], of [BB4] = [BB2,BB3] \end_layout \begin_layout Standard c) domVect of [BB4] = BB1 ... here we are not sure if BB2 or BB3 was executed but we are SURE that BB1 was executed. \end_layout \begin_layout Chapter Acknowledgments \end_layout \begin_layout Standard \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sdcc.sourceforge.net/#Who \end_layout \end_inset \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \emph on Thanks to all the other volunteer developers who have helped with coding, testing, web-page creation, distribution sets, etc. You know who you are :-) \emph default \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \emph on Thanks to Sourceforge \begin_inset Flex URL status collapsed \begin_layout Plain Layout http://sourceforge.net/ \end_layout \end_inset which has hosted the project since 1999 and donates significant download bandwidth. \emph default \begin_inset Newline newline \end_inset \begin_inset Newline newline \end_inset \emph on Also thanks to all SDCC Distributed Compile Farm members for donating CPU cycles and bandwidth for snapshot builds. \begin_inset Newline newline \end_inset \end_layout \begin_layout Standard This document was initially written by Sandeep Dutta and updated by SDCC developers. \end_layout \begin_layout Standard All product names mentioned herein may be trademarks \begin_inset Index idx status collapsed \begin_layout Plain Layout Trademarks \end_layout \end_inset of their respective companies. \end_layout \begin_layout Section* Alphabetical index \end_layout \begin_layout Standard To avoid confusion, the installation and building options for SDCC itself (chapter 2) are not part of the index. \end_layout \begin_layout Standard \begin_inset CommandInset index_print LatexCommand printindex type "idx" name "Index" literal "true" \end_inset \end_layout \end_body \end_document