按键控制led灯亮灭编写程序_51单片机实现4个按键控制8个LED灯四种状态

#include<reg51.h>
sbit p3_0=P3^0;
sbit p3_1=P3^1;
sbit p3_2=P3^2;
sbit p3_3=P3^3;
void delay(unsigned char i);
void main()
{ 
  unsigned char ledctr;
  P3=0xff;
  while(1)
  {
    ledctr=P3;
	switch(ledctr)
	{
	  case 0xff:P1=0x00;break;				
	  case 0xfe:P1=0xff;break;				
	  case 0xfd:P1=0x55;delay(200);P1=0xaa;delay(200);break;	   
	  case 0xfb:P1=0xf0;break;									
	  case 0xf7:P1=0x0f;break;										 
	  
	  default:;
	 }
	}
} 
void delay(unsigned char i)
{
  unsigned char j,k;
  for(k=0;k<i;k++)
  for(j=0;j<255;j++);
}