// 對24C02的讀、寫
// extern void DelayMs(unsigned int);
// extern void Read24c02(unsigned char *RamAddress,unsigned char RomAddress,unsigned char bytes);
// extern void Write24c02(unsigned char *RamAddress,unsigned char RomAddress,unsigned char bytes);

/***************************************************************************/
#define WriteDeviceAddress 0xa0
#define ReadDviceAddress 0xa1
#include <reg52.h>
#include <stdio.h>
#include <absacc.h>
/***************************************************************************/
sbit SCL=P2^7;
sbit SDA=P2^6;
bit DOG;

/***************************************************************************/
void DelayMs(unsigned int number) {
 unsigned char temp;
 for(;number!=0;number--,DOG=!DOG) {
  for(temp=112;temp!=0;temp--) {
  }
 }
}

/***************************************************************************/
void Start() {
 SDA=1;
 SCL=1;
 SDA=0;
 SCL=0;
}

/***************************************************************************/
void Stop() {
 SCL=0;
 SDA=0;
 SCL=1;
 SDA=1;
}

/***************************************************************************/
void Ack() {
 SDA=0;
 SCL=1;
 SCL=0;
 SDA=1;
}

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

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

/***************************************************************************/
void Write8Bit(unsigned char input) {
 unsigned char temp;
 for(temp=8;temp!=0;temp--) {
  SDA=(bit)(input&0x80);
  SCL=1;
  SCL=0;
  input=input<<1;
 }
}

/***************************************************************************/
void Write24c02(unsigned char *Wdata,unsigned char RomAddress,unsigned char number) {
 Start();
 Write8Bit(WriteDeviceAddress);
 TestAck();
 Write8Bit(RomAddress);
 TestAck();
 for(;number!=0;number--) {
  Write8Bit(*Wdata);
  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();
}