M:/USB-BDI/USB-BDI/Firmware/MPC555-USB-BDI/src/uart.c

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/*      USB-BDI Used for programming and debugging a MPC555 over USB
 * 
 *  Copyright 2005 NTB Interstate University of Applied Sciences of Technology Buchs
 *
 *  This program 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 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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.
 */

#include "isr.h"
#include "dispatch.h"
#include "usbpdi_common.h"
#include "usbpdi_main.h"
#include "UART.h"
#include "fx2regs.h"
#include "delay.h"

volatile unsigned short uart0OutBufferStart = 0;
volatile unsigned short uart0OutBufferEnd = 0;
volatile unsigned short uart0InBufferStart = 0;
volatile unsigned short uart0InBufferEnd = 0;
__xdata volatile unsigned char uart0OutBuffer[UART_BUF_LEN];
__xdata volatile unsigned char uart0InBuffer[UART_BUF_LEN];
unsigned char tmpBuffer;


static void isr_uart0(void) __interrupt{
        unsigned short uart0InBufferLen;

        if (RI) {       // character has been received
                RI = 0;
                // write data to buffer
                uart0OutBuffer[uart0OutBufferEnd] = SBUF0;
                uart0OutBufferEnd = (uart0OutBufferEnd + 1) % UART_BUF_LEN;
                // move the start position if the length is at the maximum
                // thats to overwrite the oldest data (at the start), the length will not change
                if (uart0OutBufferEnd == uart0OutBufferStart){
                        uart0OutBufferStart = (uart0OutBufferStart + 1) % UART_BUF_LEN;
                }
        }
        if (TI) {       // character has been sent
                TI = 0;
                Uart0TriggerSend();
        }
}
/*
void isr_uart1(void) __interrupt
{
        if (RI1) {      // character has been received
                // buffer = SBUF1;
                RI1 = 0;
                // SBUF1 = buffer;
        }
        if (TI1) {      // character has been sent
                // SBUF1 = buffer;
                TI1 = 0;
        }
}
*/

void initUART()
{
        // Timer 1, Baud Rate = 9600bps
        PCON |= 0x80;                   // baud rate doubler enable (SMOD0)
        SMOD1 = 1;                              // baud rate doubler enable (SMOD1)
        CKCON |= 0x10;                  // (CKCON.4) Timer 1 uses CLKOUT/4
        TMOD |= 0x20;                   // Mode 2 for Timer 1
        TH1 = 0xB2;                             // set baud rate (9600bps)
        TR1 = 1;                                // enable Timer 1
        // Serial Port 0
        SM0 = 0; SM1 = 1;       // Mode 1
        REN = 1;                        // receive enabled
        hook_sv(SV_SERIAL_0, (unsigned short) isr_uart0);       // install interrupt handler
        TI = 0;                         // clear transmit interrupt
        tmpBuffer = SBUF0;              // empty the buffer
        RI = 0;                         // clear receive interrupt
        ES0 = 1;                        // Enable Serial Port 0 Interrupts
        /*
        // Serial Port 1
        SM01 = 0; SM11 = 1;     // Mode 1
        REN1 = 1;                       // receive enabled=1 disable=0
        //hook_sv(SV_SERIAL_1, (unsigned short) isr_uart1);     // install interrupt handler
        TI1 = 0;                        // clear transmit interrupt
        tmpBuffer = SBUF1;      // empty the buffer
        RI1 = 0;                        // clear receive interrupt
        //ES1 = 1;                      // Enable Serial Port 1 Interrupts
        ES1 = 0;                        // Disable Interrupts for debuging
        */
}
void changeBaudRate(unsigned long bitRate){
        TR1 = 0; //disable timer 1
        TH1 = 255-750000/bitRate;
        TR1 = 1;//enable timer 1
}