单片机按键时，数码管会闪烁一下。原因是什么

只看该作者 · 2016-11-9 21:17

#include<reg52.h>
#define uchar unsigned char
#define uint unsigned int
uchar  tt,bai,shi,ge;
uint count=300;
uchar code table[]={
0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71};
sbit dula=P2^6;
sbit wela=P2^7;
sbit key1=P3^4;
sbit key2=P3^5;
void delay(uchar z);
void init();
void key();
void display(uint count);
void main()
{
      dula=1;
      P0=0;
      dula=0;
      wela=1;
      P0=0xf8;
      wela=0;
      init();
      while(1)
      {
            key();
            display(count);


      }
}

void delay(uchar z)
{
      int i,j;
      for(i=z;i>0;i--)
            for(j=110;j>0;j--);
}

void init()
{
      TMOD=0x01;
      TH0=(65536-50000)/256;
      TL0=(65536-50000)%256;
      EA=1;
      ET0=1;

}

void timer_0() interrupt 1
{
      TH0=(65536-50000)/256;
      TL0=(65536-50000)%256;
      tt++;
      if(tt==20)
      {
            tt=0;
            count--;
      }
}

void key()
{
      if(key1==0)
      {
            delay(10);
            if(key1==0)
            {
                     TR0=1;

            }
            while(!key1);
      }
}

void display(uint count)
{
         delay(10);
            bai=count/100;
            shi=(count-bai*100)/10;
            ge=count%10;

            dula=1;
            P0=table[bai];
            dula=0;
            P0=0xff;
            wela=1;
            P0=0xfe;
            wela=0;
            delay(2);

            dula=1;
            P0=table[shi];
            dula=0;
            P0=0xff;
            wela=1;
            P0=0xfd;
            wela=0;
            delay(3);

            dula=1;
            P0=table[ge];
            dula=0;
            P0=0xff;
            wela=1;
            P0=0xfb;
            wela=0;
                     delay(3);

}

按键按下，数码管只显示最后一个个位，好无奈啊，试了好长时间！