24C04A，只能读，写不成功，奇怪了。高手指点一下。谢谢

只看该作者 · 2010-7-9 00:46

#include <iom16v.h>
#include <macros.h>
#define uchar unsigned char;
#define uint  unsigned int;
//-----定义I2总线端口, 可根据实际使用改变----
#define SCL_L PORTA&=~BIT(0) //I2总线时钟线
#define SCL_H PORTA|=BIT(0)
#define SDA_L PORTA&=~BIT(1) //I2总线数据线
#define SDA_H PORTA|=BIT(1)

#define SDA_TO_IN DDRA&=~BIT(1) _NOP() //设数据线位输入
#define SDA_TO_OUT DDRA|=BIT(1) _NOP() //设数据线位输出

#define SDA_IF_L (PINA&BIT(1))==0  //如果sda为低
#define SDA_IF_H (PINA&BIT(1))==BIT(1) //如果sda为高
#define DELAY_us _NOP(); _NOP(); _NOP(); _NOP();_NOP();
unsigned char temp1,temp2,writedevice_add=0xa0,readdevice_add=0xa1,word_address=0,word_address1=0,word_address2=0,word_data=0,dd;
//a:writedevice add
//a1:readdevice add
//b:wordbyte add
//c:byte_data
//d:write8bit_cs;
//*************************************************
void delay_for_eeprom()
{
  _NOP();_NOP();_NOP();_NOP();_NOP();_NOP(); _NOP();_NOP();_NOP();_NOP();_NOP();_NOP();
  _NOP();_NOP();_NOP();_NOP();_NOP();_NOP();
  _NOP();_NOP();_NOP();_NOP();_NOP();_NOP();
}
//**********************EEPROM 启动适用24c02**************************/
void start_cs2()

{ SDA_TO_OUT; //置为输出状态
delay_for_eeprom();
SDA_H;
delay_for_eeprom();
SCL_H;
delay_for_eeprom();
SDA_L;
delay_for_eeprom();
SCL_L;
delay_for_eeprom();
}
//**********************EEPROM 停止适用24c02 **************************/
void stop_cs2() {
SDA_TO_OUT; //置为输出状态
delay_for_eeprom();
SCL_L;
delay_for_eeprom();
SDA_L;
delay_for_eeprom();
SCL_H;
delay_for_eeprom();
  SDA_H;
delay_for_eeprom();
SCL_L;
delay_for_eeprom();
}
/***************************EEPROM 应答 24c02 ************************************************/
//内部函数
//********************************************************************************************
void read_ack_cs2()  //
{  SDA_TO_OUT; //置为输出状态
delay_for_eeprom();
SDA_L;
delay_for_eeprom();
SCL_H;
delay_for_eeprom();
SCL_L;
delay_for_eeprom();
  }
/***************************EEPROM 应答 24c04 ************************************************/
void  write_ack_cs2(void)
{
SDA_TO_OUT;
   delay_for_eeprom();
  SDA_L;
   delay_for_eeprom();
  SCL_H;
  delay_for_eeprom();
  SCL_L;
  delay_for_eeprom();
  }
/***************************EEPROM 写数据 24c02 ************************************************/
void  write8bit_cs2(writedevice_address)
{
unsigned char temp;
SDA_TO_OUT;
   delay_for_eeprom();
//置为输出状态
for(temp=8;temp!=0;temp--)
{
  if(0x80==(writedevice_address & 0x80) )
      {
         SDA_H;
         }
      else
      {
         SDA_L;
         }
      delay_for_eeprom();
   SCL_H;
      delay_for_eeprom();
  SCL_L;
  delay_for_eeprom();
  writedevice_address=writedevice_address<<1;
  delay_for_eeprom();
   }
   }
//***************************EEPROM 读数据 24c02************************************************/
unsigned char read8bit_cs2()
{
unsigned char output;
   delay_for_eeprom();
  SDA_TO_IN; //置为输入状态
for(temp1=8;temp1!=0;temp1--)
{
   SDA_H;
      delay_for_eeprom();
  SCL_H;
  delay_for_eeprom();

      if(SDA_IF_H)
  {
output=output<<1;
output|=0x01;
}
  else
      {output=output<<1;}

  delay_for_eeprom();
  SCL_L;
  delay_for_eeprom();
  }
   return(output);
   }
//***************************EEPROM 读数据 24c02*****************************************
//内部函数：带参数返回
////2004-4-10:增加写重试功能
//**************
char read_eeprom_byte(word_address)  //
{
start_cs2(); //start
delay_for_eeprom();
write8bit_cs2(0xa0);  //device address
read_ack_cs2();
write8bit_cs2(word_address);    //word address
read_ack_cs2();
start_cs2();       //start
write8bit_cs2(0xa1);  //device address
read_ack_cs2();
word_data=read8bit_cs2();    //读出1
read_ack_cs2();
stop_cs2();
return(word_data);
}
//*************************************************************************
//写数据到EEPROM
//入口：word_address,word_data
//2004-4-10:增加写重试功能
//************************************************************************
void write_eeprom_byte(word_address,word_data)  //b-byteadd ,c_data
{
   stop_cs2();
   delay_for_eeprom();
   start_cs2();
   write8bit_cs2(0xa0);  //device address
write_ack_cs2;
   write8bit_cs2(word_address);  //byte address //b
write_ack_cs2;
   write8bit_cs2(word_data);  //byte_data
write_ack_cs2();
stop_cs2();
  }