51单片机 LED 循环点亮代码优化：两种模式切换

#include<reg52.h> #define LED P1

void delay(unsigned int x) { unsigned int i,j; for(i=0;i<x;i++) for(j=0;j<100;j++); }

void main() { unsigned char flag=0; unsigned char i;

while(1)
{
    if(flag ==0)
    {
        for(i=0;i<8;i++)
        {
            LED=~(1<<i);
            delay(500);
        }
    }
    else
    {
        for(i=7;i>=0;i--)
        {
            LED=~(1<<i);
            delay(500);
        }
    }
}

}

void key_interrupt() interrupt 1 { static unsigned char flag =0; flag=!flag; }