40+

40秒倒计时

#include<iom16.h>
unsigned char led[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
unsigned int CNT;
signed int FOR=500;
void delay(unsigned char x)
{
unsigned char i,j;
for(i=0;i<100;i++)
 for(j=0;j<x;j++);
}
void main(void)
{
unsigned char g,s;
CNT=39;
DDRA=0XFF;
DDRB=0XFF;
TCCR0=1<<CS01;
OCR0=248;
TIMSK=1<<OCIE0;
SREG|=0x80;
while(1)
{
s=CNT/10;
g=CNT%10;
PORTA=led[s];
PORTB=0xfe; 
delay(10);
PORTB=0xff;
PORTA=led[g];
PORTB=0xfd;
delay(10);
PORTB=0xff;
}
}
#pragma interrupt_handler int_djs:20
void int_djs(void)
{
FOR--;
if(FOR==0)
{FOR=500;
CNT--;
if(CNT<=0)
CNT=39;}
TCNT0=0;
}