我显示的动态扫描怎么让他停留

 这是一个基于51hei-5型开发板的原程序~~~

#include<reg52.h>
 #include"51hei.h"
 #define uchar unsigned char
  #define ui unsigned int
sbit D1=P2^1;
sbit SJ=P1^4;
sbit D2=P0^1;
sbit D3=P0^6;
sbit wes=P2^7;
sbit dus=P2^6;
sbit X1=P3^2; 
unsigned int a,b,c,d,y,a2,a1,a0, HuanChong;
 uchar code table[]={
  0x3f,0x06,0x5b,0x66,0x6d,0x7d,0x07,0x7f,0x6f                 
                     };
 void delay_ (unsigned int  ms) ;
  void  display(ui bi,ui si,ui ge)
{uchar i;
    
 P0=table[bi];
 dus=1;
 dus=0;
 P0=0xdf;
 wes=1;
 wes=0;
    delay_(1);
 P0=0xff;
    wes=1;
    wes=0;
 for(i=50;i>0;i--);
 
 P0=table[si];
 dus=1;
 dus=0;
 P0=0xbf;
 wes=1;
 wes=0;
    delay_(1);
    P0=0xff;
    wes=1;
    wes=0;
 for(i=50;i>0;i--);
 
 P0=table[ge];
 dus=1;
 dus=0;
 P0=0x7f;
 wes=1;
 wes=0;
    delay_(1);
 P0=0xff;
    wes=1;
    wes=0;
 for(i=50;i>0;i--);
}
void main()
{ 
guandz();
if(X1==0){
delay_(1);
if(X1==0){
wes=1;
P0=0xff;
wes=0;
SJ=0;
y=120;
delay_(1); 
 do{ 
    D1=0;
    D2=0;
    D3=1;
   delay_ (100000);
    D1=1;
    D2=1;       
    D3=0;
  delay_ (2000);
   HuanChong=y;
 a2=HuanChong/100;
 a1=HuanChong%100/10;
    a0=HuanChong%100%10;
    display(a2,a1,a0);

 } 
   while(y--);
  } }}  

 void delay_ (unsigned int  ms)
{
  unsigned char x;
 while(ms--)
 for(x=0;x<120;x++);
}

 求改进 ~ 我想让数码管显示到下一次改变的数的时候

不懂你的意思呢，再表述清楚一点吧