51对24c256进行读写一字节

#include<reg52.h>
#define uchar unsigned char
sbit sda=P2^0;
sbit scl=P2^1;
uchar a;
void delay()
{ ;; }
void start()  //开始信号
{
sda=1;
delay();
scl=1;
delay();
sda=0;
delay();
}

void stop()   //停止
{
sda=0;
delay();
scl=1;
delay();
sda=1;
delay();
}

void respons()  //应答
{
uchar i;