51对24c256进行读写一字节

发布时间：2013-10-08 16:08:16

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#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;
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 delay1(uchar x)
{
uchar a,b;
for(a=x;a>0;a--)
for(b=100;b>0;b--);
}

void write_add(uchar address1,uchar address2,uchar date)
{
start();
write_byte(0xa0);
respons();
write_byte(address1);
respons();
write_byte(address2);

respons();
write_byte(date);
respons();
stop();
}

uchar read_add(uchar address1,uchar address2)
{
uchar date;
start();
write_byte(0xa0);
respons();
write_byte(address1);
respons();
write_byte(address2);
respons();
start();
write_byte(0xa1);
respons();
date=read_byte();
stop();
return date;
}

void main()
{
init();
write_add(23,24,0x00);
delay1(100);
P1=read_add(23,24);
while(1);
}