#include<reg51.h>
#define uint unsigned int
#define uchar unsigned char
uchar code KEY_TABLE[]={
  0xee,0xde,0xbe,0x7e,
  0xed,0xdd,0xbd,0x7d,
  0xeb,0xdb,0xbb,0x7b,
  0xe7,0xd7,0xb7,0x77
  };
uchar code TABLE[]={
  0x3F,0x06,0x5B,0x4F,
  0x66,0x6D,0x7D,0x07,
  0x7F,0x6F,0x77,0x7c,
  0x39,0x5e,0x79,0x71
  };
void delay()
{
  uint n =50000;while(n-- );
}
void delays()
{
  uint n= 10000;while(n--);
}
main()
{
  uchar temp,key,num,i;
    while(1)
    {
      P3= 0xf0;
        if(P3!= 0xf0)
        {
          delays();
            if(P3!= 0xf0)
            {
              temp= P3;
              P3= 0x0f;
              key= temp|P3;
                for(i= 0;i<16;i++)
                if(key== KEY_TABLE[i])
                {
                  num= i;break;
                }
                P2= TABLE[num];
                delay();
            }
        }
    }
}