原地召唤大佬！！

请大佬们看看下面的程序
想让单片机从0数秒到9999，看了一下午，奈何找不到错误
#include "reg52.h"
#define GPIO_DIG P0
typedef unsigned char u8;
typedef unsigned int u16;
sbit LSA=P2^2;
sbit LSB=P2^3;
sbit LSC=P2^4;
u8 code smg[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,
0x7c,0x39,0x5e,0x79,0x71};
u8 DisplayData[8]={0};
u16 Second=0;
void delay(u16 i)
{
while(i--);
}
void Timer0Init()
{
TMOD|=0X01;
TH0=0xfc;
TL0=0x18;
ET0=1;
EA=1;
TR0=1;
}
void Digdisplay()
{
u8 i;
for(i=0;i<8;i++)
{
switch (i)
{
case 0:LSA=0;LSB=0;LSC=0;break;
case 1:LSA=1;LSB=0;LSC=0;break;
case 2:LSA=0;LSB=1;LSC=0;break;
case 3:LSA=1;LSB=1;LSC=0;break;
case 4:LSA=0;LSB=0;LSC=0;break;
case 5:LSA=1;LSB=0;LSC=1;break;
case 6:LSA=0;LSB=1;LSC=1;break;
case 7:LSA=1;LSB=1;LSC=1;break;
}
GPIO_DIG=DisplayData[i];
delay(100);
P0=0X00;
}
}
void main()
{
Second=1;
Timer0Init();
while(1)
{
if(Second<=9999)
{
DisplayData[0]=smg[(Second/1000)];
DisplayData[1]=smg[(Second/100)%10];
DisplayData[2]=smg[(Second/10)%10];
DisplayData[3]=smg[(Second/1)%10];
DisplayData[4]=DisplayData[0];
DisplayData[5]=DisplayData[1];
DisplayData[6]=DisplayData[2];
DisplayData[7]=DisplayData[3];
}else
{
Second=1;
}
}
}
void Timer0() interrupt 1
{
static u16 i;
TH0=0XFC;
TL0=0X18;
i++;
if(i==1000)
{
i=0;
Second++;
}
}