#include<reg52.h>
#include<intrins.h>
#define uint unsigned int
#define uchar unsigned char
uchar temp;
void delay(uint);
void main()
{
temp=0xfe;
P1=temp;
while(1)
{
temp=_crol_(temp,1);
delay(600);
}
}
void delay()
{
uint x,y;
for(x=100;x>0;x--)
for(y=20;y>0;y--);
}