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Diffstat (limited to 'device/lib/_ser.c')
| -rw-r--r-- | device/lib/_ser.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/device/lib/_ser.c b/device/lib/_ser.c new file mode 100644 index 0000000..923eb0f --- /dev/null +++ b/device/lib/_ser.c @@ -0,0 +1,184 @@ +/*------------------------------------------------------------------------- + _ser.c - this file contains a simple interrupt driven serial driver with + buffer (no check for overflow!!!). + + Copyright (C) 1999, Sandeep Dutta <sandeep.dutta AT ieee.org> + + 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. +-------------------------------------------------------------------------*/ + +/*KA****************************************************************** +* PROJECT: PL-One/8052 +********************************************************************** +* FILE: ser.c +********************************************************************** +* CHANGES: +* date author description +* -------------------------------------------------------------------- +* 04/26/99 we final +* 04/27/99 we comments +********************************************************************** +* DESCRIPTION: +* This file contains a simple interrupt driven serial driver with +* buffer (no check for overflow!!!). +********************************************************************** +* FUNCTIONS DECLARED: +* ser_init Initialization; must be called first +* ser_putc output one char on the serial line +* ser_getc return a char if one has been received, else 0 +* ser_printString print a 0-terminated string +* ser_charAvail return 1 if a char arrived on serial line +********************************************************************** +* NOTE: +* Remember to enable all interrupts (EA=1) outside of this module!! +********************************************************************** +* COMPILE TIME OPTIONS: - +* DEBUG OPTIONS: - +******************************************************************KE*/ + +#include <8052.h> + +#include "ser.h" + +#define NON_BLOCKING + +unsigned char __xdata ser_txIndexIn; +unsigned char __xdata ser_txIndexOut; +unsigned char __xdata ser_rxIndexIn; +unsigned char __xdata ser_rxIndexOut; + +unsigned char __xdata ser_txBuffer[0x100]; +unsigned char __xdata ser_rxBuffer[0x100]; + +static __bit ser_txBusy; + +void +ser_init(void) +{ + ES = 0; + + ser_txBusy = 0; + + ser_txIndexIn = 0; + ser_txIndexOut = 0; + ser_rxIndexIn = 0; + ser_rxIndexOut = 0; + + T2CON = 0x30; + + /* Baudrate = 19200, oscillator frq. of my processor is 21.4772 MHz */ + RCAP2H = 0xFF; + RCAP2L = 0xDD; + + /* enable counter */ + T2CON = 0x34; + + SCON = 0x50; + + if (TI) { + TI = 0; + } + if (RI) { + RI = 0; + } + + ES=1; +} + +void +ser_interrupt_handler(void) __interrupt 4 __using 1 +{ + ES=0; + + if (RI) { + RI = 0; + ser_rxBuffer[ser_rxIndexIn++] = SBUF; + } + + if (TI) { + TI = 0; + if (ser_txIndexIn == ser_txIndexOut) { + ser_txBusy = 0; + } + else { + SBUF = ser_txBuffer[ser_txIndexOut++]; + } + } + + ES=1; +} + +void +ser_putc(unsigned char c) +{ + ES=0; + + if (ser_txBusy) { + ser_txBuffer[ser_txIndexIn++] = c; + } + else { + ser_txBusy = 1; + SBUF = c; + } + + ES=1; +} + +unsigned char +ser_getc(void) +{ + char tmp; + +#ifdef NON_BLOCKING + if (ser_rxIndexIn != ser_rxIndexOut) { + tmp = ser_rxBuffer[ser_rxIndexOut++]; + } + else { + tmp = 0; + } +#endif + + return(tmp); +} + +void +ser_printString(char *String) +{ + while (*String) { + ser_putc(*String++); + } +} + +char +ser_charAvail(void) +{ + char ret = 0; + + if (ser_rxIndexIn != ser_rxIndexOut) { + ret = 1; + } + + return(ret); +} + +/*********************End of File************************************/ |