ADC0809做简易电压表，用1602显示

时钟信号是用ALE四分频后提供的，单片机用的晶振是12MHz，但是显示不出结果，请问是什么问题
#include<reg52.h>
#define uchar unsigned char
#define uint unsigned int
sbit rs=P1^0;
sbit rw=P1^1;
sbit en=P1^2;
sbit clk=P1^6;
sbit st=P1^3;
sbit eoc=P1^4;
sbit oe=P1^5;
uchar code table[]={"Voltage"};
void delay(uchar z)
{
uchar x,y;
for(x=z;x>0;x--)
for(y=110;y>0;y--);
}
void write_com(uchar com)
{
rs=0;
rw=0;
P2=com;
delay(5);
en=1;
delay(5);
en=0;
}
void write_data(uchar shuju)
{
rs=1;
rw=0;
P2=shuju;
delay(5);
en=1;
delay(5);
en=0;
}
void lcd_init()
{
uchar t;
en=0;
write_com(0x38);
write_com(0x01);
write_com(0x0c);
write_com(0x06);
write_com(0x80);
for(t=0;t<7;t++)
{
write_data(table[t]);
}
}
void main()
{
uchar date,ge,shi,bai;
lcd_init();
while(1);
{
st=0;
st=1;
st=0;
while(eoc==0);
oe=1;
date=P0;
oe=0;
bai=date/100;
shi=date%100/10;
ge=date%10;
write_com(0x80+0x40);
write_data(bai+0x30);
write_com(0x80+0x41);
write_data(shi+0x30);
write_com(0x80+0x42);
write_data(ge+0x30);
}
}