#include <REG52.H>
sbit duan=P1^1;
sbit wei=P1^0;
#define shuju P2
unsigned char duan_ma[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,
0x07,0x7f,0x6f,0x77,0x7c,0x39,0x5e,0x79,0x71,};
unsigned char wei_ma[]={0x7f,0xbf,0xdf,0xef,0xf7,0xfb,0xfd,0xfe};
void delay_ms(unsigned int ms)
{
  unsigned int  j;
  while(ms--)
  for(j=0;j<120;j++);
}
void led_show_delay_us(unsigned int us)
{
while(us--);
}
void led_show_number(unsigned char len,unsigned long int num)
{
  unsigned char n;
  unsigned char temp[8];
  temp[7]=num%100000000/10000000;
  temp[6]=num%10000000/1000000;
  temp[5]=num%1000000/100000;
  temp[4]=num%100000/10000;
  temp[3]=num%10000/1000;
  temp[2]=num%1000/100;
  temp[1]=num%100/10;
  temp[0]=num%10/1;
  if(len>8)len=8;
  for(n=0;n<len;n++)
  {
   duan=0;
      wei=1;
     P0=wei_ma[n];
  wei=0;
  duan=1;
  P0=duan_ma[temp[n]];
  led_show_delay_us(100);
  }
}
#define key_port P3
unsigned char keys_scan()
{
   unsigned char keyno=16,M;
   key_port=0x0f;
   delay_ms(1);
   M=key_port^0x0f;
   switch(M)
   {
   case 1:keyno=0;break;
   case 2:keyno=1;break;
   case 4:keyno=2;break;
   case 8:keyno=3;break;
   default:keyno=16;
   }
   key_port=0xf0;
   delay_ms(1);
   M=key_port^0xf0;
   switch(M)
   {
    case 16:keyno+=0;break;
case 32:keyno+=4;break;
case 64:keyno+=8;break;
case 128:keyno+=12;break;
   }
   return   keyno;
   
   
}
void main()
{
unsigned long int key_no;
   while(1)
   {
P3=0Xf0;
if(P3!=0Xf0)
{
  key_no= keys_scan();
  while(!(P3==0Xf0));
}
    led_show_number(8,key_no);
   }
}
如何才能让0~9、A~F这16个数字依次向左或者向右移动呢，求给位大神帮忙！程序应如何改