#include<reg52.h>
#define uchar unsigned char
#define uint unsigned int
sbit fengmingqi=P0^0; //聲明IO口
void delay(uint x)//延時子函數
{
uint i,j;
for(i=x;i>0;i--)
for(j=50;j>0;j--);
}
void main(void)
{
while(1) //循環
{
fengmingqi=1; //p0.0口高電平，蜂鳴器發聲
delay(500); //延時
fengmingqi=0; //p0.0口低電平，蜂鳴器不發聲
delay(500); //延時
}
}