AT89S52-based 24C02 usage

#define uchar unsigned char
#define uint unsigned int
sbit scl=P3^4;
sbit sda=P3^5;
void delay0()//about 4us delay
{
 ;;
}
void delay(uint z)//about 1ms delay
{
 uint x,y;
 for(x=z;x>0;x--)
  for(y=110;y>0;y--);
}
void start()//start signal
{
 sda=1;
 delay0();
 scl=1;
 delay0();
 sda=0;
 delay0(); 
}
void stop()//stop signal
{
 sda=0;
 delay0();
 scl=1;
 delay0();
 sda=1;
 delay0();
}
void respons()//response signal
{
 uchar i;
 scl=1;
 delay0();
 while(sda==1&&i<250)i++;//Wait for response
 scl=0;
 delay0();
}
void write_byte(uchar date)//Write data, write one byte
{
 uchar i;
 scl=0;
 delay0();
 for(i=0;i<8;i++)
 {
  date=date<<1;
  sda=CY;//Move the highest bit into the CY bit of PSW
  delay0();
  scl=1;
  delay0();
  scl=0;
  delay0();
 }
 sda=1;//Release the sda ​​line
 delay0();
}

uchar read_byte()//read data, read one byte
{
 uchar i,j;
 scl=0;
 delay0();
 sda=1;
 delay0();
 for(i=0;i<8;i++)
 {
  scl=1;
  delay0();
  j=(j<<1)|sda;
  scl=0;
  delay0();
 }
 return j;
}
void write_add(uchar address,uchar date)//write one byte of data to a certain address
{
  start();//start signalwrite_byte
  (0xa0);//device address+0, i.e. 1010 000 0, the last '0' is the write direction bitrespons
  ();//responsewrite_byte
  (address);//write the first address of the devicerespons
  ();
  write_byte(date);//write datarespons
  ();
  stop();//stop signal
}
uchar read_add(uchar address)//read data from a certain address
{
  uchar l;
  start(); //start signal 
  write_byte(0xa0); //device address + 0, i.e. 1010 000 0, the last '0' is the write direction bit
  respons();
  write_byte(address); //first address to be read
  respons();
  start(); //start signal again
  write_byte(0xa1); //device address + 1, i.e. 1010 000 1, the last '1' is the read direction bit
  respons();
  l=read_byte(); //read data 
  stop();
  return l; //return data 
}
void init_24C02() //24C02 initialization
{
 sda=1; //release data line
 delay0();
 scl=1; //release clock line
 delay0();
}
void main()
{
 init_24C02();
 while(1)
 {
  write_add(1,0x00);
  delay(100); //Delay is necessary because there needs to be a certain time interval between writing and reading the device, otherwise it will not react quickly
  P2=read_add(1); //Read the data in 24C02, "1" is its storage address
  while(1);  
 }
}