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; -------------------------------------------------------------------------
; _gptrget2.S - read two bytes pointed to by a generic pointer
;
; Copyright (C) 2005, Raphael Neider <rneider AT web.de>
;
; This library is free software; you can redistribute it and/or modify it
; under the terms of the GNU General Public License as published by the
; Free Software Foundation; either version 2, or (at your option) any
; later version.
;
; This library is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
; GNU General Public License for more details.
;
; You should have received a copy of the GNU General Public License
; along with this library; see the file COPYING. If not, write to the
; Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
; MA 02110-1301, USA.
;
; As a special exception, if you link this library with other files,
; some of which are compiled with SDCC, to produce an executable,
; this library does not by itself cause the resulting executable to
; be covered by the GNU General Public License. This exception does
; not however invalidate any other reasons why the executable file
; might be covered by the GNU General Public License.
;--------------------------------------------------------------------------
; calling conventions:
; 3 byte generic pointer is passed in via (WREG STK00 STK01).
; The result is returned in (WREG (STK00 (STK01 (STK02)))).
;
; unsigned char _gptrget (void *gptr);
; unsigned char _gptrget1 (void *gptr);
; unsigned int _gptrget2 (void *gptr);
; void * _gptrget3 (void *gptr);
; unsigned long _gptrget4 (void *gptr);
;
; void _gptrput (void *ptr, unsigned char val);
; void _gptrput1 (void *ptr, unsigned char val);
; void _gptrput2 (void *ptr, unsigned int val);
; void _gptrput3 (void *ptr, unsigned int val);
; void _gptrput4 (void *ptr, unsigned long val);
include macros.inc
include p16f_common.inc
global __gptrget2
extern __codeptrget1
CODE
__gptrget2:
select_routine __dataptrget2, __codeptrget2
; invalid tag -- return 0x0000
clrf STK00
retlw 0x00
__dataptrget2:
setup_fsr
movf _INDF, W
movwf STK00 ; low byte in STK00
inc_fsr
movf _INDF, W ; high byte in WREG
return
__codeptrget2:
pagesel __codeptrget1 ; might reside in different page
call __codeptrget1
movwf STK02 ; temporarily store LSB
incfsz STK01,F ; increment low address byte
decf STK00,F ; undo increment of high address byte if low byte did not overflow
incf STK00,F ; increment high address byte
pagesel __codeptrget1 ; might reside in different page
call __codeptrget1
movwf STK03 ; temporarily store MSB
movf STK02, W
movwf STK00 ; LSB in STK00
movf STK03, W ; MSB in WREG
return
END
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