C流水灯

#include <reg51.h>

 // 延时子程序
void delayms(unsigned char ms)
{
unsigned char i;
while(ms--)
{
for(i = 0; i < 120; i++);       //又机器周期决定，1ms包含多少个执行次数。执行120次空指令
}
}

main()
{
unsigned char LED;   
LED = 0xfe;  //0xfe = 1111 1110
  while(1)
{
     
    P1 = LED;    //P1端口赋值
delayms(250);
LED = LED << 1;    //循环左移1位，点亮下一个LED "<<"为左移位
if(LED == 0x00 )  
{ P1 = LED; LED = 0xfe;  delayms(250);  } // 0xfe = 1111 1110
}
}