led

51最小系统版实验程序

#include"reg52.h"
sbit led1=P2^4;
sbit led2=P2^5;
sbit led3=P2^6;
sbit led4=P2^7;
sbit key1=P3^2;
sbit key2=P3^3;
sbit key3=P3^4;
sbit key4=P3^5;
sbit beep=P2^0;
void delay(int t);
void main()
 { int i;
   unsigned char temp;
 
   while(1)
   {    
   temp=0x01;
    for(i=0;i<8;i++)
	{beep=~beep;
	P1=~temp;
	 delay(25);
	 temp<<=1;
	 led1=key1;
   led2=key2;
   led3=key3;
   led4=key4;
   P0=0x00;
	 }
	 }
	 }
void delay(int t)
{ int bt;
for( ;t;t--)
for(bt=0;bt<255;bt++);
}