i2c.c

一个电表的程序

/*******************************************************************************
*
*  FILE NAME	  :  i2c.c
*
*  DESCRIPTION:
*  i2c for eeprom read/write routine
*
********************************************************************************
*  INCLUDE FILES
********************************************************************************/
#include 	<machine.h>
#include 	"iodefine.h"
#include	"i2c.h"
#include 	"extern.h"

/******************************************************************************/
#define 	SET_SDA_IN  		(IO.PCR3 = 0xc4)		
#define 	SET_SDA_OUT			(IO.PCR3 = 0xc6)
#define 	SET_SDA_SCL_OUT 	(IO.PCR3 = 0xc6)
#define 	I2C_SDA         	(IO.PDR3.BIT.B1)
#define 	I2C_SCL				(IO.PDR3.BIT.B2)
#define 	EEPROM_WP			(IO.PDR3.BIT.B6)
#define 	EEPROM_WP_ON		(EEPROM_WP = 1)
#define 	EEPROM_WP_OFF		(EEPROM_WP = 0)

#define		Power_Io_Data		(IO.PDR5.BIT.B0)
// =======================================================================
/*对于EEROM I2C 要注意：
	1、应答信号判断,控制；
	2、页写延时
	*/
// =======================================================================		*/
/*对于EEROM I2C 要注意：
	1、应答信号判断,控制；
	2、页写延时																	*/
void I2cWStart(void)
{
	SET_SDA_SCL_OUT;
	NOP;
	NOP;
	I2C_SCL = 0;
	NOP;
	NOP;
	I2C_SDA = 1;
	NOP;
	NOP;
	I2C_SCL = 1;
	NOP;
	NOP;
	I2C_SDA = 0;
    NOP;
    NOP;
    I2C_SCL = 0;
}


// =======================================================================
void I2cStop(void)
{
	SET_SDA_OUT;	//I2C_SCL = 0; //EEPROM_i2c_scl_low();
	NOP;
	NOP;
	I2C_SCL = 0;
	NOP;
	NOP;
    I2C_SDA = 0;
    NOP;
    NOP;
    I2C_SCL = 1;
    NOP;
    NOP;
    I2C_SDA = 1;
}
// =======================================================================
void I2_SLK(void)
{
	NOP;
	I2C_SCL = 1;
	NOP;
	NOP;
	I2C_SCL = 0;
	NOP;
}
// =======================================================================
void I2cWrtBit(unsigned char data)
{
	unsigned char k;
	SET_SDA_OUT;
	for(k=0; k<8; k++) 
	{
		if(data & cMsbBitTbl[k])
			I2C_SDA = 1;	//I2cSdaHigh;
		else 
			I2C_SDA = 0;	//	I2cSdaLow;
		I2_SLK ();
	}
}
// =======================================================================
unsigned char ee_ack()
{
	unsigned char ack;
	SET_SDA_IN;
	ack = 0;
	NOP;
	I2C_SCL = 1;
	NOP;
	if(I2C_SDA == 1)
		ack = 1;
	I2C_SCL = 0;	//如果延长SCL时间可使I2C_SDA = 1 ？？？,在SCL =1前可对SDA做任何改动
	NOP;
	I2C_SDA = 0;	//所以要在更改为outport 前=0 ？？？
	return ack;
}

// =======================================================================
unsigned char I2cRBit(void)
{
	unsigned char data,j;
	SET_SDA_IN;
	data = 0;
	for(j=0;j<8;j++) 
	{
		I2C_SCL = 1;I2C_SCL = 1;
        if(I2C_SDA ==1 )	//IsI2cSdaHigh)
			data |= cMsbBitTbl[j];
		I2C_SCL = 0;
	}
	return data;
}
// =======================================================================
void I2c_ACK(void)
{
	SET_SDA_OUT;
	I2C_SDA = 0;
	NOP;
	I2_SLK();
}
// =======================================================================
void I2c_NACK(void)
{
	SET_SDA_OUT;
	I2C_SDA = 1;
	NOP;
	I2_SLK();
}
// =======================================================================
void delay_10ms(void)
{
  unsigned int delay_timer;
  for(delay_timer =0;delay_timer<4000;delay_timer++)
   {
	 NOP;
	} 
}	

/*********************************************************************************************************/
unsigned char  F_BlckRead_Eeprm(unsigned int Data_SAdr,unsigned char   *Data,unsigned char Data_Len)
{
  unsigned char mack,i,Loop,j,F_ee_ok=0;
  if (Data_Len==0)
   {
	 return F_ee_ok;
	} 
  j=Data_Len;	 
  F_ee_ok = 0;
  Loop=0x03;
  while(Loop--)
   {
     I2cWStart();
     I2cWrtBit (CHIP_ADDR|((unsigned char )(Data_SAdr>>8)<<1) );
     mack = ee_ack();
     I2cWrtBit ((unsigned char )Data_SAdr);
     mack |= ee_ack();
     I2cWStart();
     I2cWrtBit ((CHIP_ADDR|((unsigned char )(Data_SAdr>>8)<<1)) |0x01);
     mack |= ee_ack();
     for ( i=1;i<Data_Len;i++)
	  {

		*Data++ = I2cRBit();
		I2c_ACK(); 
       }
     *Data = I2cRBit();
     if(!mack)
      {
        F_ee_ok=1;
        break;
       }
     else
      {
        Data_SAdr=Data_SAdr-j;
	    Data=Data-j;
	    Data_Len=j;
       }
     }  
  I2c_NACK();
  I2cStop();
  return F_ee_ok;
}
// =======================================================================
unsigned char   F_BlckWrt_Eeprm(unsigned int 	Data_SAdr,unsigned char  *Data,unsigned char 	Data_Len)
{
  unsigned char Loop,mack,i,j,F_ee_ok=0;
  if (Data_Len==0)
   {
	 return F_ee_ok;
	} 
  j=Data_Len;	
  EEPROM_WP_OFF;
now_star:
  Loop=3;
  while(Loop-- !=0)
   {
     F_ee_ok = 0;
     I2cWStart();
     I2cWrtBit (CHIP_ADDR|((unsigned char)(Data_SAdr>>8)<<1) );
     mack = ee_ack();
     I2cWrtBit ((unsigned char)Data_SAdr);
     mack |= ee_ack();
     for (i=0;i<Data_Len;i++)
      {
	    I2cWrtBit(*Data++);
	    mack |= ee_ack();
        Data_SAdr+=1;
	    if((!(Data_SAdr&0x0f)) &&(!mack))
	     {
		   I2cStop();
		   delay_10ms();
		   Data_Len-=(i+1);
		   goto now_star;
   	      }
	   }
     if(!mack)
      {
	    F_ee_ok = 1;		//表示EEROM操作成功
	    break;
	   }
	 Data_SAdr=Data_SAdr-j;
	 Data=Data-j;
	 Data_Len=j;
	}
  I2cStop();
  for (i =0;i<10;i++)
   {
	 NOP;
	 NOP;
	 NOP;
	 NOP;
	}
  EEPROM_WP_ON;
  delay_10ms();
  return F_ee_ok;
}