十六进制计数器.doc

实验程序：

#include <reg51.h>

#include <stdio.h>

#define uchar unsigned char

#define key_prot P3

bit run=0;

uchar buf[4]={0,0,0,0};

code uchar tab[16] ={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90,0x88,0x83,

0xc6,0xa1,0x86,0x8e};

code uchar kcode[16]={0xee,0xde,0xbe,0x7e,0xed,0xdd,0xbd,0x7d,0xeb,0xdb,0xbb,0x7b,

0xe7,0xd7,0xb7,0x77};

code uchar scn[4]={0xfe,0xfd,0xfb,0xf7};

void delay(uchar ms)

{

  uchar i,j;

  for(i=0;i<100;i )

      {

          for(j=0;j<ms;j );

      };

}

uchar key(void)

{

  uchar a,r,key_port;

  r=0xff;

  delay(200);

  if(key_port==0xf0) goto rn;

  a=key_port;

  key_port=a|0x0f;

      delay(200);

      a=key_port;

      for(r=0;r<16;r )

      { if(a==kcode[r])break;};

          if(r>15)r=0xff;

      rn: key_port=0xf0;

          return r;

      }

void main(void){

  uchar c, i;

  EA=1;

  TMOD=0x01;

  ET0=1;

  TH0=0xec;

  TL0=0x78;

  TR0=1;

  while(1)

  {

      c=key();

      if(c<16)

      {   for(i=0;i<3;i ) buf[i]=buf[i 1];

          buf[3]=c;

      }

  }

}

void timeint(void) interrupt 1

{ static char i;

  TH0=0xec;

  TL0=0x78;

  P0=0xff;

  P0=tab[buf[i]];

  P2 =scn[i];

  i ;

  i=i&0x03;

}