at2402读写程序.c

这是一个读写AT2402EEPROM的程序.由C语言编写,程序结构简单,程序代码少,编译出来的HEX代码也少,占用ROM空间超小.

//超高效的读写程序
//AT2402读写程序
#include<reg52.h>
#include<intrins.h>
sbit WP=P2^1;
sbit SCL=P2^2;
sbit SDA=P2^3;

void AT2402START(void)
{SCL=1;
SDA=1;
_nop_();
_nop_();
SDA=0;
_nop_();
_nop_();
}

void AT2402STOP(void)
{
SDA=0;
SCL=1;
_nop_();
SDA=1;
_nop_();
}

void ACK(void)
{bit at2402;
SDA=1;
SCL=1;
_nop_();
at2402=SDA;
_nop_();
SCL=0;
}

void DELAY (unsigned int time)
{while(time--);}

void BYTEWRITE(unsigned char BYTEVAL)
{unsigned char i;

for(i=0;i<8;i++)
{SCL=0;
_nop_();
_nop_();
SDA=(bit)(BYTEVAL&0X80);
BYTEVAL=BYTEVAL<<1;
SCL=1;
_nop_();
SCL=0;
}}

unsigned char BYTEREAD(void)
{unsigned char READVAL;
unsigned char i;
READVAL=0;
for(i=0;i<8;i++)
{
SDA=1;
SCL=0;
_nop_();
_nop_();
_nop_();
SCL=1;
_nop_();
READVAL=READVAL<<1;
READVAL=READVAL|(unsigned char)SDA;
_nop_();
}
return(READVAL);

}
void main(void)
{WP=0;
AT2402START();

BYTEWRITE(0XA0);
ACK();
BYTEWRITE(0X20);
ACK();
BYTEWRITE(0X65);
ACK();
AT2402STOP();
DELAY(1000);
AT2402START();

BYTEWRITE(0XA0);
ACK();
BYTEWRITE(0X20);
ACK();
AT2402START();
BYTEWRITE(0XA1);
ACK();
P1=BYTEREAD();
AT2402STOP();
while(1);
}