为啥iic的写入和读取之间要加延时，没加延时读取不正常-----------------------------------------------
以下程序用郭天祥例程改的-------------------------------------
单片机源程序如下:
#include<reg52.h>
#define uchar unsigned char
#define uint unsigned int
bit write=0; //写24C02的标志；
sbit sda=P2^0;
sbit scl=P2^1;
void delay()
{ ;; }
void delay1ms(uint z)
{
uint x,y;
for(x=z;x>0;x--)
for(y=110;y>0;y--);
}
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;
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(0xa0);
respons();
write_byte(address);
respons();
write_byte(date);
respons();
stop();
}
uchar read_add(uchar address)
{
uchar date;
start();
write_byte(0xa0);
respons();
write_byte(address);
respons();
start();
write_byte(0xa1);
respons();
date=read_byte();
stop();
return date;
}
void main()
{
init();
delay1ms(12);
delay1ms(1);
write_add(2,0xa1);
delay1ms(1);
P1=read_add(2);
while(1);
}
源码用郭天祥例程改的
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