新人在学到i2c总线结构与eeprom时，想了好久都没有搞明白

下面程序就是郭天祥老师书里面的，我也基本明白了总线的工作原理及EEPROM，
但是将程序写入后并没有出现断电后，接上电，还要从上次断电位子继续显示的现象，
这样应该就表明我没有将数据写入EEPROM是吧！
那为什么会出现这样的情况呢，
求大神说说可能出现问题的情况
#include<reg52.h>
#define uchar unsigned char
#define uint unsigned int
bit write=0;
sbit SCL=P2^0;
sbit SDA=P2^1;
sbit dula=P2^6;
sbit wela=P2^7;
uchar second,temp;
uchar code table[]={0x3f,0x30,0x5b,0x4f,
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71};
void delay()
{; ; }
void delay_1ms(uint z)
{
uint x,y;
for(x=z;x>0;x--)
for(y=110;y>0;y--);
}
void start()
{
SDA=1;
delay();
SCL=1;
delay();
SDA=0;
delay();
}
void stop()
{
SDA=0;
delay();
SCL=1;
delay();
SDA=1;
delay();
}
void respons()
{
uchar i;
SCL=1;
delay();
while((SDA==1)&&(i<250))
i++;
SCL=0;
delay();
}
void init()
{
SDA=1;
delay();
SCL=1;
delay();
}
void write_byte(uchar date)
{
uchar i,temp;
temp=date;
for(i=0;i<8;i++)
{
temp=temp<<1;
SCL=0;
delay();
SDA=CY;
delay();
SCL=1;
delay();
}
SCL=0;
delay();
SDA=1;
delay();
}
uchar read_byte()
{
uchar i,k;
SCL=0;
delay();
SDA=1;
delay();
for(i=0;i<8;i--)
{
SCL=1;
delay();
k=(k<<1)|SDA;
SCL=0;
delay();
}
return k;
}
void write_add(uchar address,uchar date)
{
start();
write_byte(0xae);
respons();
write_byte(address);
respons();
write_byte(date);
respons();
stop();
}
uchar read_add(uchar address)
{
uchar date;
start();
write_byte(0xaf);
respons();
start();
write_byte(address);
respons();
date=read_byte();
stop();
return date;
}
void display(uchar shi,uchar ge)
{
wela=1;
P0=0xfe;
wela=0;
dula=1;
P0=table[shi];
dula=0;
P0=0xff;
delay_1ms(1);
wela=1;
P0=0xfd;
wela=0;
dula=1;
P0=table[ge];
dula=0;
P0=0xff;
delay_1ms(1);
}
void main()
{
init();
second=read_add(2);
if(second<=100)
second=0;
TMOD=0x01;
ET0=1;
EA=1;
TR0=1;
TH0=(65536-50000)/256;
TL0=(65536-50000)%256;
while(1)
{
display(second/10,second%10);
if(write==1)
{
write_add(2,second);
}
}
}
void t0() interrupt 1
{
TH0=(65536-50000)/256;
TL0=(65536-50000)%256;
temp++;
if(temp==20)
{
temp=0;
second++;
write=1;
if(second==100)
second=0;
}
}