#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() //终止信号
{
sda=0;
delay();
scl=1;
delay();
sda=1;
delay();
}
void respons() //应答
{
uchar i;
scl=1;
delay();
while((sda==1)&&(i<250))//器件应答数据线变为0,因为总线空闲时均为高电平
i++;
scl=0;
delay();
}
void init()
{
sda=1;
delay();
scl=1;
delay();
}
void write_byte(uchar date)//写一个字节
{
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;//不用就释放
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 delay1(uchar x)
{
uchar a,b;
for(a=x;a>0;a--)
for(b=100;b>0;b--);
}
void write_add(uchar address,uchar date)//在指定地址写一个数据
{
start();
write_byte(0xa0);
respons();
write_byte(address);
respons();
write_byte(date);
respons();
stop();
}
uchar read_add(uchar address)//在指定地址读一个数据
{
uchar date;
start();
write_byte(0xa0);
respons();
write_byte(address);
respons();
start();//收到应答后51要重复一次起始信号
write_byte(0xa1);
respons();
date=read_byte();
stop();
return date;
}
void main()
{
init();
write_add(23,0xaa);//xie
delay1(100);
P1=read_add(23);//du
while(1);
}