设计ADC0809与单片机8031的硬件接口，并编写A⼀D转换程序？谢谢

#include "reg51.h"
#define data_point P0
sbit EOC=P2^0;
sbit ADDA=P2^1;
sbit ADDB=P2^2;
sbit ADDC=P2^3;
sbit OE=P2^5;
sbit START=P2^6;
sbit CLK=P2^7;
sbit ALE=P2^6;
unsigned char disp[3]={0,0,0};
char code dispcode[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,0x80,0x90};
unsigned char t0count=0;
void display()
{
unsigned char i,j,k=0x01;
for(i=0;i<3;i++)
{
P1=1;
P3=disp[i];
P1=k;
k<<=1;
for(j=200;j>0;j--);
}
P1=0;
}
unsigned char ADC0808()
{
unsigned char d;
ADDC=0;
ADDB=0;
ADDA=0;
TR1=1;
ALE=1;ALE=0;
START=1;START=0;

while(EOC==0);
OE=1;
d=data_point;
OE=0;
TR1=1;
return d;
}
void covert(unsigned char x)
{disp[0]=dispcode[x/50];
disp[0]=disp[0]+0x80;
x=(x%50)*2;
disp[1]=dispcode[x/10];
disp[2]=dispcode[x%10];
}
void main()
{
TMOD=0x21;
TH0=(65536-10000)/256;
TL0=(65536-10000)%256;
TH1=256-2;
ET0=1;
ET1=1;
EA=1;
TR0=1;
OE=0;
START=0;
EOC=1;
while(1)
{
display();
}
}
void time0() interrupt 1
{
TH0=(65536-10000)/256;
TL0=(65536-10000)%256;
t0count++;
if(t0count==100)
{
t0count=0;
covert(ADC0808());
}
}
void time1() interrupt 3
{
CLK=~CLK;
}