第1个回答 2018-06-04
#include<reg51.h>
#define uchar unsigned char
uchar cnt;
sbit led=P1^0;
sbit ldr=P3^2;
void ext0() interrupt 0
{
TR0=1;
}
void t0isr() interrupt 1
{
TH0=(65536-50000)/256;
TL0=(65536-50000)%256;
cnt++;
if(cnt>=40)
{
cnt=0;
led=~led;
}
}
main()
{
TMOD=0x01;
TH0=(65536-50000)/256;
TL0=(65536-50000)%256;
ET0=1;
EX0=1;
IT0=0;
EA=1;
while(1)
{
if(ldr==1)TR0=0;
}
}本回答被提问者和网友采纳