用A/D转换芯片TLC2543CN测量电压并在LED数码管显示时LED数码管闪烁

我想A/D转换芯片TLC2543CN测量电压并在LED数码管显示出来，在Proteus里面模拟的好好的，可实际做出来的电路板上数码管总是闪烁，请大师帮忙看看是哪里出了问题。
#include<reg51.h>
#include<intrins.h>
#define uint unsigned int
#define uchar unsigned char
sbit TCL2543_SDO=P0^0;
sbit TCL2543_SDI=P0^1;
sbit TCL2543_CS=P0^2;
sbit TCL2543_CLK=P0^3;
sbit TCL2543_EOC=P0^5;
uchar code table[]={
0x3f,0x06,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71};
void delayus(uchar u);
uint ReadADC_TLC2543(uchar ain);
void display(uchar L1,uchar L2,uchar L3);
uchar ECO,u,L1,L2,L3;
unsigned long num;
void main()
{       
        TCL2543_CS=1;
        TCL2543_CLK=0;
        while(1)
        {
                num=ReadADC_TLC2543(0);
                L1=num/1000;
                L2=num%1000/100;
                L3=num%100/10;
                display(L1,L2,L3);
        }
}
void delayus(unsigned char u)
{
    while(--u);
}
uint ReadADC_TLC2543(uchar ain)
{
    uchar temp;
    uint adc_value = 0;
    ain <<= 4;
    TCL2543_CS = 0;
    for(temp = 0;temp < 12;temp ++)
    {
        adc_value <<= 1;
        ain <<= 1;
        TCL2543_SDI = CY;
        if(TCL2543_SDO)   adc_value += 1;
        TCL2543_CLK = 1;
        delayus(1);
        TCL2543_CLK = 0;
    }
    TCL2543_CS = 1;
    return  adc_value;
}
void display(uchar L1,uchar L2,uchar L3)
{
                P1=table[L1];
                P2=table[L2];
                P3=table[L3];
}

Proteus模拟正常