原创 MCF52211读写24c256的程序

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

** File:i2c_driver.h

** the MCF52211 microcontroller's i2c module driver header file

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

#ifndef _LZP_MCF52211_I2C_DRIVER_H_
#define _LZP_MCF52211_I2C_DRIVER_H_

void init_i2c();

void i2c_start();
unsigned char i2c_send_byte(unsigned char c);
unsigned char i2c_recv_byte(unsigned char ack);
void i2c_stop();
void i2c_restart();
#endif

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

** File:i2c_driver.c

** The MCF52211 Microcontroller's i2c module driver

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

#include "support_common.h" /* include peripheral declarations and more */
#include "i2c_driver.h"

void init_i2c()
{
 unsigned char temp;
 
 MCF_GPIO_PASPAR  |=MCF_GPIO_PASPAR_SCL0_SCL0 |MCF_GPIO_PASPAR_SDA0_SDA0 ;
 MCF_I2C_I2FDR(0)=MCF_I2C_I2FDR_IC(0x38);//about 100khz
 MCF_I2C_I2ADR(0)=0xf0;
 MCF_I2C_I2CR(0)=0x80;//enable i2c
// MCF_I2C1_I2CR=0;
 if(MCF_I2C_I2SR(0)&MCF_I2C_I2SR_IBB)
 {
  MCF_I2C_I2CR(0)=0x0;
  MCF_I2C_I2CR(0)=MCF_I2C_I2CR_IEN |  /* enable module */
        MCF_I2C_I2CR_MSTA;
  temp=MCF_I2C_I2DR(0);
  MCF_I2C_I2SR(0)=0;
  MCF_I2C_I2CR(0)=0x0;
  MCF_I2C_I2CR(0)=0x80;//enable i2c
 }
}

void i2c_start()
{
 while(MCF_I2C_I2SR(0)&MCF_I2C_I2SR_IBB);
 MCF_I2C_I2CR(0)|=MCF_I2C_I2CR_MTX ;
 MCF_I2C_I2CR(0)|=MCF_I2C_I2CR_MSTA ; 
}

unsigned char i2c_send_byte(unsigned char c)
{
// MCF_I2C0_I2CR|=MCF_I2C_I2CR_MTX ;
// if(MCF_I2C0_I2SR|MCF_I2C_I2SR_IAL)
// {
  //arbitration lost
//  MCF_I2C0_I2SR&=~MCF_I2C_I2SR_IAL ;
// }
// i2c_start();
// MCF_I2C_I2CR(0)|=MCF_I2C_I2CR_MTX ;
// MCF_I2C_I2CR(0)|=MCF_I2C_I2CR_MSTA ;
 MCF_I2C_I2DR(0)=c;
 while((MCF_I2C_I2SR(0)&MCF_I2C_I2SR_IIF)==0)
 {
  
 }

 MCF_I2C_I2SR(0)&=~MCF_I2C_I2SR_IIF;
 if(MCF_I2C_I2SR(0)&MCF_I2C_I2SR_RXAK) 
  return 1;//failed
 else
     return 0;//success
}

unsigned char i2c_recv_byte(unsigned char ack)
{
 unsigned char temp;
 if(ack>0)
 {
  MCF_I2C_I2CR(0)|=MCF_I2C_I2CR_TXAK; 
 }
 else
 {
  MCF_I2C_I2CR(0)&=~MCF_I2C_I2CR_TXAK;  
 }
 
 MCF_I2C_I2CR(0)&=~MCF_I2C_I2CR_MTX ;
 temp=MCF_I2C_I2DR(0); 
 while((MCF_I2C_I2SR(0)&MCF_I2C_I2SR_IIF)==0)
 {
  
 }
 MCF_I2C_I2SR(0)&=~MCF_I2C_I2SR_IIF;
 temp= MCF_I2C_I2DR(0);
 while((MCF_I2C_I2SR(0)&MCF_I2C_I2SR_IIF)==0)
 {
  
 }
 MCF_I2C_I2SR(0)&=~MCF_I2C_I2SR_IIF;
 return temp;
}

void i2c_stop()
{
 MCF_I2C_I2CR(0)&=~MCF_I2C_I2CR_MSTA ; 
}

void i2c_restart()
{
 MCF_I2C_I2CR(0)|=MCF_I2C_I2CR_RSTA;
}

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

**File: at24c256.h

** AT24c256 eeprom driver's header file

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

#ifndef _LZP_MCF52211_AT24C256_H_
#define _LZP_MCF52211_AT24C256_H_
#include "support_common.h"

#define EEPROM_MAX_ADDR  32768
#define WR24C256 0xA0
#define RD24C256 0xA1

unsigned char at24c256_write(unsigned char *buf,unsigned char num,uint16 addr);
unsigned char  at24c256_read(unsigned char *buf, unsigned char num, uint16 addr);
#endif

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

** File: at24c256.c

**at24c256's driver

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

#include "i2c_driver.h"
#include "at24c256.h"
#include "delay.h"

/* write 24xxxx I2C EEPROM
* 参数:
* buf---包含待写入数据的缓冲区
* addr---eeprom起始地址
* num--数据长度
* 返回:
* 0---success
* 1---failed
* 2---invalid address
*/
unsigned char at24c256_write(unsigned char *buf,unsigned char num,uint16 addr)
{
 unsigned char i,ret;
 
 if(addr+num>EEPROM_MAX_ADDR)
  return 2;
 
 i2c_start();
 ret=i2c_send_byte(WR24C256);
 if(ret)
 {
  i2c_stop();
  return 1;
 }
 i=(uint8)((addr&0xff00)>>8);
 ret=i2c_send_byte(i);
 if(ret)
 {
  i2c_stop();
  return 1;
 }
 i=(uint8)(addr&0x00ff);
 ret=i2c_send_byte(i);
 if(ret)
 {
  i2c_stop();
  return 1;
 }
 for(i=0;i<num;i++)
 {
  if(i2c_send_byte(buf))
  {
   i2c_stop();
   return 1;
  }
 }
 i2c_stop();
 delay_ms(5);
 return 0;
}
 
/*read 24xxxx I2C EEPROM
* arguments:
* buf---return  the data
* addr---address of cell you want to write
* num--the numner of data we want to read
* return:
* 0---success
* 1---failed
* 2---invalid address
*/
unsigned char  at24c256_read(unsigned char *buf, unsigned char num, uint16 addr)
{
 unsigned char i,ret;
 
 if(addr+num>EEPROM_MAX_ADDR)
  return 2;
 
 i2c_start();
 if(i2c_send_byte(WR24C256))
 {
  i2c_stop();
  return 1;
 }
 i=(uint8)((addr&0xff00)>>8);
 ret=i2c_send_byte(i);
 if(ret)
 {
  i2c_stop();
  return 1;
 }
 i=(uint8)(addr&0x00ff);
 ret=i2c_send_byte(i);
 if(ret)
 {
  i2c_stop();
  return 1;
 }
 i2c_restart();
 if(i2c_send_byte(RD24C256))
 {
  i2c_stop();
  return 1;
 }
 
 for(i=0;i<num-1;i++)
 {
  buf=i2c_recv_byte(0);
 }
 buf[i++]=i2c_recv_byte(1);
 i2c_stop();
 return 0;
}