#include<reg52.h>
#include<intrins.h>
#define uint unsigned int
#define uchar unsigned char;
uchar temp;
uint a;
sbit beep=P2^5;
void delay();
void main()
{
temp=0xfe;
P1=temp;
beep=0;
while(1)
{
temp=_crol_(temp,1);
P1=temp;
delay();
}
}
void delay()
{
uint x,y;
for(x=0;x<350;x++)
for(y=0;y<500;y++);
}