24c02.c

WAVE6000 编写的AT24C02驱动 用于掉电数据保护

#include <reg51.h>

// 对24C02的读、写
 void DelayMs(unsigned int);
 void delay1ms();
 void delay(char k);
 void Read24c02(unsigned char *RamAddress,unsigned char RomAddress,unsigned char bytes);
 void Write24c02(unsigned char *RamAddress,unsigned char RomAddress,unsigned char bytes);
 void Start();
 void Stop();
 void Ack();
 void NoAck();
 bit TestAck();
 bit Write8Bit(unsigned char input);
 unsigned char Read8Bit();
/***************************************************************************/
#define WriteDeviceAddress 0xae
#define ReadDviceAddress 0xaf

/***************************************************************************/
sbit SCL=P3^4;
sbit SDA=P3^5;
sbit  tt=ACC^5;
//sbit DOG=P3^7;

 /***************************************************************************/

 void main()
 {
   int i;
   unsigned char  wdata[10],rdata[10],temp,temp1;
   for( i=0;i<10;i++)
   {

      wdata[i]=i+1;
    }

   Write24c02(wdata,0x00,10);

   Read24c02(rdata,0x00,10);
   temp=rdata[0];
   temp1=temp;
   temp=rdata[1];
   temp=rdata[2];
   temp=rdata[3];
   temp=rdata[4];
   while(1)
   {
   temp =10;
   }
 }

 /***************************************************************************/
void DelayMs(unsigned int number) {
    unsigned  int i;
   for( i=0;i< number;i++)
    delay1ms();

}

/***************************************************************************/
void Start() {

 SCL=0;
SDA=1;
delay(50);

tt=1;
SCL=1;
SCL=tt;
delay(50);
SDA=0;
delay(50);
SCL=0;
//delay(50);
}

/***************************************************************************/
void Stop() {

SCL=0;
//delay(50);
SDA=0;
delay(50);
tt=1;
SCL=tt;
SCL=tt;
delay(50);
SDA=1;
delay(50);
}

/***************************************************************************/
void Ack() {
tt=0;
SDA=tt;
//delay(50);
tt=1;
SCL=1;

delay(50);
SCL=0;
//delay(50);
//SDA=1;
}

/***************************************************************************/
void NoAck() {
SDA=1;
delay(50);
SCL=SDA;
delay(50);
SCL=0;
delay(50);
}

/***************************************************************************/
bit TestAck() {
   bit ErrorBit;
    SDA=1;
    SCL=1;
    ErrorBit=SDA;
    SCL=0;
    return(ErrorBit);
}

/***************************************************************************/
bit Write8Bit(unsigned char input) {
unsigned char temp;
for(temp=0;temp<8;temp++) {

//SDA=(bit)(input&0x80);
if( input&0x80)
  SDA=1;
else SDA=0;
SCL=1;
delay(50);
SCL=0;
input=0xc0;
input=input<<1;
}
}

/***************************************************************************/
void Write24c02(unsigned char *Wdata,unsigned char RomAddress,unsigned char number) {
  int  k;
  k=0;
  Start();
  Write8Bit(WriteDeviceAddress);
   tt=1;
  tt=TestAck();
Write8Bit(RomAddress);
  tt=TestAck();
for(;number!=0;number--) {
  Write8Bit(*Wdata);
  tt=TestAck();
  Wdata++;
  }
Stop();
DelayMs(10);
}

/***************************************************************************/
unsigned char Read8Bit() {
unsigned char temp,rbyte=0;
for(temp=8;temp!=0;temp--) {
SCL=1;
rbyte=rbyte<<1;
rbyte=rbyte|((unsigned char)(SDA));
SCL=0;
}
return(rbyte);
}

/***************************************************************************/
void Read24c02(unsigned char *RamAddress,unsigned char RomAddress,unsigned char bytes) {
  unsigned char temp,rbyte;
  Start();
   Write8Bit(WriteDeviceAddress);
   TestAck();
   Write8Bit(RomAddress);
   TestAck();
   Start();
   Write8Bit(ReadDviceAddress);
   TestAck();
   while(bytes!=1) {
   *RamAddress=Read8Bit();
   Ack();
   RamAddress++;
   bytes--;
}
*RamAddress=Read8Bit();
NoAck();
Stop();
}
void delay1ms()
{
 IE=00;
 TMOD=0x10;
 TH1=0xfc;
 TL1=0x23;
 TR1=1;

 while(!TF1);
 TF1=0;
}
void delay(unsigned char k)
{
  unsigned char i;
  for(i=0;i<k;i++) ;

}