#include<reg52.h>
#include<intrins.h>
#define uchar unsigned char
#define uint unsigned int
sbit P20=P2^0;sbit P21=P2^1;sbit P22=P2^2;
sbit P24=P2^4;sbit P25=P2^5;sbit P26=P2^6;sbit P27=P2^7;
unsigned char code ledk[17]={0x3f,0x06,0x5b,0x4f,0x66,0x6D,0x7d,0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71,0x00};
unsigned char mask=0xee,key,x=15;
sbit P37=P3^7;sbit P10=P1^0;
sbit clk=P0^7;sbit sda=P0^6;             
//=============================
void delay (unsigned int n)
{unsigned int i,j;
 for(i=0;i<n;i++)
   for(j=0;j<n ;j++);   }
void shift(dd)
  {unsigned char j=0;
	while(j<8){if((dd&0x80)!=0)sda=1;else sda=0;
				   clk=0; clk=1; dd<<=1;j++;}	}
//---------disp-----------
void display(x)
{uchar i;
 for(i=0;i<=7;i++)
 {shift(ledk[x]);
   P20=i&0x04;P21=i&0x02;P22=i&0x01;
   delay(15);
  }
} 
  
//-------------
unsigned char get_char(void)
{unsigned char	key_code;
  static unsigned char column=0;
  if (P37!=0)key_code=0xff;
     else key_code=column;
  mask=_crol_(mask,1);
  P24=mask&0x10;P25=mask&0x20;P26=mask&0x40;P27=mask&0x80;
  column++;
  if(column>3)column=0; 
  return(key_code);}
void key_func(key)
 {switch (key)
   {case 0:x=0;break;  
    case 1:x=1;break;  
    case 2:x=2;break;  
    case 3:x=3;break;
    default: break;}  }
void main(void)
{ P10=0; 
while(1)
     {key=get_char( );key_func(key);display(x);}		   
 }