sdcc-3.9.0 fork implementing GNU assembler syntax

This fork aims to provide better support for stm8-binutils

1 files changed, 108 insertions, 0 deletions

diff --git a/device/lib/serial.c b/device/lib/serial.c
new file mode 100644
index 0000000..01c4e81
--- /dev/null
+++ b/device/lib/serial.c
@@ -0,0 +1,108 @@
+/*-------------------------------------------------------------------------
+   serial.c - this module implements serial interrupt handler and IO
+              routinwes using two 256 byte cyclic buffers. Bit variables
+              can be used as flags for real-time kernel tasks
+
+   Copyright (C) 1996, Dmitry S. Obukhov <dmitry.obukhov AT gmail.com>
+
+   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.
+-------------------------------------------------------------------------*/
+
+/* This module contains definition of I8051 registers */
+#include "8052.h"
+
+
+static unsigned char __xdata stx_index_in, srx_index_in, stx_index_out, srx_index_out;
+static unsigned char __xdata stx_buffer[0x100];
+static unsigned char __xdata srx_buffer[0x100];
+
+static __bit work_flag_byte_arrived;
+static __bit work_flag_buffer_transfered;
+static __bit tx_serial_buffer_empty;
+static __bit rx_serial_buffer_empty;
+
+
+void serial_init(void)
+{
+    SCON = 0x50;
+    T2CON = 0x34;
+    PS = 1;
+    T2CON = 0x34;
+    RCAP2H = 0xFF;
+    RCAP2L = 0xDA;
+    
+    RI = 0;
+    TI = 0;
+    
+    stx_index_in = srx_index_in = stx_index_out = srx_index_out = 0;
+    rx_serial_buffer_empty = tx_serial_buffer_empty = 1;
+    work_flag_buffer_transfered = 0;
+    work_flag_byte_arrived = 0;
+    ES=1;
+}
+
+void serial_interrupt_handler(void) __interrupt 4 __using 1
+{
+    ES=0;
+    if ( RI )
+	{
+	    RI = 0;
+	    srx_buffer[srx_index_in++]=SBUF;
+	    work_flag_byte_arrived = 1;
+	    rx_serial_buffer_empty = 0;
+	}
+    if ( TI )
+	{
+	    TI = 0;
+	    if (stx_index_out == stx_index_in )
+		{
+		    tx_serial_buffer_empty = 1;
+		    work_flag_buffer_transfered = 1;
+		}
+	    else SBUF = stx_buffer[stx_index_out++];
+	}
+    ES=1;
+}
+
+/* Next two functions are interface */
+
+void serial_putc(unsigned char c)
+{
+    stx_buffer[stx_index_in++]=c;
+    ES=0;
+    if ( tx_serial_buffer_empty )
+	{
+	    tx_serial_buffer_empty = 0;
+	    TI=1;
+	}
+    ES=1;
+}
+
+unsigned char serial_getc(void)
+{
+    unsigned char tmp = srx_buffer[srx_index_out++];
+    ES=0;
+    if ( srx_index_out == srx_index_in) rx_serial_buffer_empty = 1;
+    ES=1;
+    return tmp;
+}