从低位到高位流动的闪烁灯

 #include<reg51.h>
 #include<intrins.h>
 #define  uint unsigned int
 #define  uchar unsigned char
 void delay(uint x )
 {
   uint i,j;
   for(i=x;i>0;i--)
    for(j=110;j>0;j--);
 }
 void main()
  { 
    P0=0xfe;
    while(1)
 {
     P0=_crol_(P0,1);
  delay(100);
 }
  }