求教 Atmega8 无法进入外中断

只看该作者 · 2015-3-5 22:11

ATmega8 无法进入外中断，程序如下，目的是发生一次外中断累加一次data_1,并通过串口送到PC，上电后串口调试助手只能收到一次01，如果能进入中断应该能收到04啊，求教。多谢
#include <avr/io.h>

/***********************************宏定义**********************************/
#define fosc 11059200 //晶振8MHZ
#define baud 9600 //波特率

unsigned char data_1;//每触发一次中断，该值加1
unsigned char flag;//发生int0中断后，该值置0xFF

void uart0_init(void)
{
UCSRB = 0x00;
UCSRA = 0x00;
UCSRC =(1<<UCSZ1)|(1<<UCSZ0);
UBRRL=(fosc/16/(baud+1))%256;
UBRRH=(fosc/16/(baud+1))/256;
UCSRB =(1<<RXEN)|(1<<TXEN);
}

void int0_init(void)
{
MCUCR=(1<<ISC01);//INT0下降沿触发中断
GICR=(1<<INT0);//enable INT0
}

SIGNAL(SIG_INTERRUPT0)
{
cli();
flag=0xff;
putchar0(4);
sei();
}

void putchar0(unsigned char c)
{
while (!(UCSRA&(1<<UDRE)));
UDR=c;
}

int main(void)
{
uart0_init();
int0_init();
putchar0(1);
sei();

while(flag==0xff)
{
cli();
flag=0;

if(data_1<=255)
{
putchar0(data_1);
putchar0(2);
}
else
{
data_1=0;
putchar0(3);
}
sei();
}
}

只看该作者 · 2015-3-5 22:28

PD2外接有上啦电阻，按键按下时，用万用表量，PD2上却是有个有1->0的变化，为什么下降沿没产生中断呢？

只看该作者 · 2015-3-6 09:42

#include <avr/interrupt.h>

1万 · 2015-3-7 18:16

/*
* vs_proj2.c
*
* Created: 2015-3-7 14:16:35
*  Author: keliang.yao
*/

#define F_CPU 11059200ul

#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>

#define fosc 11059200ul
#define baud 9600ul

unsigned char data_l;
unsigned char flag;

void usart0_init(void)
{
UCSRB = 0x00;
UCSRA = 0x00;
UCSRC = (1<<UCSZ1)|(1<<UCSZ0);
UBRRL = (fosc/16/(baud+1))%256;
UBRRH = (fosc/16/(baud+1))/256;
UCSRB = (1<<RXEN)|(1<<TXEN);
}

void putchar0(unsigned char c)
{
while(!(UCSRA & (1<<UDRE)));
UDR = c;
}

void int0_init(void)
{
MCUCR = (1<<ISC01);
GICR = (1<<INT0);
}

SIGNAL(INT0_vect)
{
cli();
flag = 0xff;
putchar0(4);
sei();
}

int main(void)
{
usart0_init();
int0_init();
putchar0(1);
DDRB = 0XFF;
PORTB = 0X00;
sei();
      while(1)
   {
      //TODO:: Please write your application code
while(flag == 0xff)
{
cli();
flag = 0;
if(data_l <= 255)
{
putchar0(data_l);
putchar0(2);
}
else
{
data_l = 0;
putchar0(3);
}
sei();
}
      }
}
楼主试试这样