#include<reg52.h>
#include<intrins.h>

#define uchar unsigned char
#define uint  unsigned  int

sbit cs=P3^4;
sbit wr=P3^6;
sbit rd=P3^7;

sbit aa=P2^0;
sbit bb=P2^1;
sbit cc=P2^2;
sbit LE1=P2^7;
uchar code table[]={ 0x3f,0x06,0x5b,0x4f,0x66,
                     0x6d,0x7d,0x07,0x7f,0x6f};
void init();
void ad_start();
uchar  ad_read();
void display(uchar bai,uchar shi,uchar ge );
void delay(uint t)  //延時程序
{
  uint i;
  for(;t>0;t--)
    for(i=110;i>0;i--);
}


void main()
{
   uchar adout,a1,a2,a3;
   init();
   while(1)
    {
      ad_start();
         delay(10);
      adout=ad_read();
      P1=ad_read();  
      a1=adout/100;
      a2=adout%100/10;
      a3=adout%100%10;
      display(a1,a2,a3);     

    }

}


void init()
{
  P1=0xff;
  P2=0xff;
  P3=0xff;


}

void ad_start()   //start convertion
{
  cs=0;
  _nop_();
  wr=0;
  _nop_();
  wr=1;
  _nop_();
  cs=1; 
}


uchar  ad_read()
{
  uchar temp;
  P1=0xff;
  cs=0;
  _nop_();
  rd=0;
  _nop_();
  temp=P1; 
  _nop_();
  rd=1;
  _nop_();
  cs=1; 
  wr=0;
  return(temp);
}

void display(uchar bai,uchar shi,uchar ge )
{
  LE1=1;//選通138
  aa=0;
  bb=0;
  cc=0;
  P0=table[bai];
  delay(1);

  aa=1;
  bb=0;
  cc=0;
  P0=table[shi];
  delay(1);

  aa=0;
  bb=1;
  cc=0;
  P0=table[ge];
  delay(1);

  P0=0;   //關閉顯示
  LE1=0;


}