为什么PIC的两个中断响应就不能正常工作了

只看该作者 · 2011-1-30 00:24

为什么PIC的两个中断响应就不能正常工作了

我用的是PIC16F877A开发板，我的程序当只含有串口接收中断处理函数时没有问题，当只含有定时中断时也没有问题，
可是当我把这两个中断响应函数放在一个程序里时，串口过一会就停在那里了不动了，但是定时器Timer0定时的led还在闪，不知道是怎么回事？
请指点一下吧,谢谢！

// based on PIC16F877A
#include<pic.h>
#define uchar unsigned char
#define uint  unsigned int
//__CONFIG(0x3B31);
#define RESTART_TIMING  0x01

unsigned int  couter = 0;
int i= 5400;

void init_UART()
{
TRISC = 0xC0;  //config Rc6, RC7 as input pin
//PORTC = 0xff;

TXSTA = 0x24; //Transmit status register
               //BRGH =1 : High baud rate bit selected
               //SYNC =0 : Asynchronous mode
RCSTA=0x90; //SPEN = 1 : serial port is enable
            //CREN = 1 : continuous receive is enable
SPBRG = 25; //ste up baud rate to 9600 bps

RCIE=1;    //enable Receive SCI interrupt

}

/////////////////////////////////////////////////////////////////
void Config_Timer0()
{
//configure Timer 0
//when crystal is 4M
OPTION = OPTION & 0xDF; //internal instruction cycle clock select
OPTION = OPTION & 0xF7; //prescaler is assigned to Timer 0 module
//OPTION = OPTION | 0x07; //1:125 proscaler
//OPTION = OPTION | 0x04;    //1:32 prescaler
PS2 = 0; //1:2
PS1 = 0;
PS0 = 0;

TMR0 = 0xc3;    //定时器初值
INTCON = INTCON | 0x20;    //TMR0IE: Enable TMR0 overflow intererupt
}

////////////////////////////////////////////
void interrupt com()
{
unsigned char uchTemp;

//if( RCIE && RCIF )
if ( RCIF )
{
  TXREG = RCREG;
  while( !TRMT );

  //nGlobalTimeFlag = RESTART_TIMING;
  //nTimeCount = 100;
}

if ( T0IF)    //how many us is interval time 512us = 0.512ms
{
      couter++;

      if( couter >= 1953 )
      {
      couter = 0;

         PORTC = PORTC | 0x01;
         while ( i> 0 )
         {
      NOP();
      i--;
         }

         PORTC = PORTC & 0xFE;
      }

      TMR0 = 0x00;

      T0IF = 0;
}

}

/////////////////////////////////////////////////////
void main()
{

int nTimeCount = 0;

GIE = 0; //Disable all unmask interrupt
PEIE = 0;

Config_Timer0();
init_UART();
PEIE=1;
GIE=1; //enable all unmask interrupt

  while(1)
{
}
}