i2c.c

LWIP在STM32裸机上的移植

    I2C_SendData(I2C1, 0); 					 //清零
	timedelay = 0;
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED))
	{
  		timedelay++;
		if(timedelay > I2C_DELAY_TIME)break;
	}
  }

  I2C_GenerateSTOP(I2C1, ENABLE);
}

/******************************************************************************
* Function Name  : I2C_EE_PageWrite
* Description    : 连续写多个字节函数
* 				 : 在一个单独的写周期内向EEPROM写入几个字节，字节个数不能大于页面大小
* Input			 :
*				 - pBuffer 		  : 指向包含要写入EEPROM的数据的缓冲区
*                - WriteAddr 	  : EEPROM的内部地址
*                - NumByteToWrite : 要写的字节个数，不能超过255
******************************************************************************/
void I2C_EE_PageWrite(u8* pBuffer, u16 WriteAddr, u8 NumByteToWrite)
{
  __IO uint32_t timedelay = 0;

  /*测试总线忙标志位*/  
  while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY))
  {
  	timedelay++;
	if(timedelay > I2C_DELAY_TIME)return;
  }
    
  /*发送开始条件*/
  I2C_GenerateSTART(I2C1, ENABLE); 
  timedelay = 0;
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT))
  {
  	timedelay++;
	if(timedelay > I2C_DELAY_TIME)return;
  }
    
  /*发送从机地址*/
  I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);
  timedelay = 0;
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED))
  {
  	timedelay++;
	if(timedelay > I2C_DELAY_TIME)return;
  }

  /*发送EEPROM在要写入数据的内部地址*/    
  //I2C_SendData(I2C1, WriteAddr);  
    
  //新加的语句
  I2C_SendData(I2C1, (WriteAddr&0xff00)>>8);// 发送前8位地址  
  timedelay = 0;
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED))  
  {
  	timedelay++;
	if(timedelay > I2C_DELAY_TIME)return;
  }

  I2C_SendData(I2C1, (WriteAddr&0xff));		// 发送后8位地址
  timedelay = 0;  
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED))
  {
  	timedelay++;
	if(timedelay > I2C_DELAY_TIME)return;
  }

  /*写入数据操作*/
  while(NumByteToWrite--)  
  {
    I2C_SendData(I2C1, *pBuffer); 
    pBuffer++;
	timedelay = 0; 
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED))
	{
  		timedelay++;
		if(timedelay > I2C_DELAY_TIME)break;
  	}
  }

  /*发送停止位*/
  I2C_GenerateSTOP(I2C1, ENABLE);
}

/******************************************************************************
* Function Name  :  I2C_EE_BufferWrite
* Description    :  向EEPROM写入数据
* Input          -  pBuffer        : 指向包含要写入EEPROM的数据的缓冲区
*                -  WriteAddr      : 要写入数据的EEPROM的内部地址
*                -  NumByteToWrite : 要写入的数据总byte
******************************************************************************/
void I2C_EE_BufferWrite(u8* pBuffer, u16 WriteAddr, u16 NumByteToWrite)
{
  /*初始化（要写入的数据）页面、非整页的byte、地址、数据计数器为0*/
  u8 NumOfPage = 0, NumOfSingle = 0, Addr = 0, count = 0;

  Addr = WriteAddr % I2C_PageSize;	/*这里求出满足整页面后还剩下的不足一页的地址*/
  count = I2C_PageSize - Addr;		/*这里求出从那一页那个地址开始写*/
  NumOfPage =  NumByteToWrite / I2C_PageSize;	/*写多少页*/
  NumOfSingle = NumByteToWrite % I2C_PageSize;	/*单独剩下多少bit*/
 
  /*如果地址页对齐，即刚好整页面，255的整数倍*/
  if(Addr == 0) 
  {
    if(NumOfPage == 0) /*表示数据量《255*/
    {
      I2C_EE_PageWrite(pBuffer, WriteAddr, NumOfSingle);
      I2C_EE_WaitEepromStandbyState();/*等待EEPROM的准备状态*/
    }
    /*如果为页面大小255的整数倍（2倍及以上）*/
    else  
    {
      while(NumOfPage--)
      {
        I2C_EE_PageWrite(pBuffer, WriteAddr, I2C_PageSize); 
    	I2C_EE_WaitEepromStandbyState();
        WriteAddr +=  I2C_PageSize;
        pBuffer += I2C_PageSize;
      }

      if(NumOfSingle!=0)
      {
        I2C_EE_PageWrite(pBuffer, WriteAddr, NumOfSingle);
        I2C_EE_WaitEepromStandbyState();
      }
    }
  }
  /*若写地址不是页对齐即不是255的整数倍*/
  else 
  {
    /*数据小于页面大小*/
    if(NumOfPage== 0) /*不够一页*/
    {
      I2C_EE_PageWrite(pBuffer, WriteAddr, NumOfSingle);
      I2C_EE_WaitEepromStandbyState();
    }
    /*数据大于一个页面*/
    else
    {
      NumByteToWrite -= count;/*字节计数*/
      NumOfPage =  NumByteToWrite / I2C_PageSize;/*写几页*/
      NumOfSingle = NumByteToWrite % I2C_PageSize;/*剩下几个单独字节*/	
      
      if(count != 0)/*数据没写完*/
      {  
        I2C_EE_PageWrite(pBuffer, WriteAddr, count);
        I2C_EE_WaitEepromStandbyState();
        WriteAddr += count;
        pBuffer += count;
      } 
      
      while(NumOfPage--)/*整页没写完*/
      {
        I2C_EE_PageWrite(pBuffer, WriteAddr, I2C_PageSize);
        I2C_EE_WaitEepromStandbyState();
        WriteAddr +=  I2C_PageSize;
        pBuffer += I2C_PageSize;  
      }
      if(NumOfSingle != 0)/*单独字节没写完*/
      {
        I2C_EE_PageWrite(pBuffer, WriteAddr, NumOfSingle); 
        I2C_EE_WaitEepromStandbyState();
      }
    }
  }  
}

/******************************************************************************
* Function Name  : I2C_EE_BufferRead
* Description    : 从EEPROM中读取一个或者多个连续字节数据
* Input			 :
* 				 - pBuffer 		 : 指向包含要写入EEPROM的数据的缓冲区
* 				 - ReadAddr 	 : 要读取数据的EEPROM的内部地址
* 				 - NumByteToRead : 要读取的数据总量
******************************************************************************/
void I2C_EE_BufferRead(u8* pBuffer, u16 ReadAddr, u16 NumByteToRead)
{
  __IO uint32_t timedelay = 0;
     
  while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY))
  {
  	timedelay++;
	if(timedelay > I2C_DELAY_TIME)return;
  }
       
  /* Send START condition */
  I2C_GenerateSTART(I2C1, ENABLE);
  timedelay = 0;
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT))
  {
  	timedelay++;
	if(timedelay > I2C_DELAY_TIME)return;
  }

  /* Send EEPROM address for write */
  I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);
  timedelay = 0;
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED))
  {
  	timedelay++;
	if(timedelay > I2C_DELAY_TIME)return;
  }
  
  /* Clear EV6 by setting again the PE bit */
  I2C_Cmd(I2C1, ENABLE);

  /* Send the EEPROM's internal address to write to */
  //I2C_SendData(I2C1, ReadAddr); 
    
  I2C_SendData(I2C1, (ReadAddr&0xff00)>>8);	// 发送前8位地址
  timedelay = 0;  
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED))
  {
  	timedelay++;
	if(timedelay > I2C_DELAY_TIME)return;
  } 

  I2C_SendData(I2C1, (ReadAddr&0xff));		// 发送后8位地址
  timedelay = 0;
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED))
  {
  	timedelay++;
	if(timedelay > I2C_DELAY_TIME)return;
  }
  
  /* Send STRAT condition a second time */  
  I2C_GenerateSTART(I2C1, ENABLE);
  timedelay = 0;
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT))
  {
  	timedelay++;
	if(timedelay > I2C_DELAY_TIME)return;
  }
    
  /* Send EEPROM address for read */
  I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Receiver);
  timedelay = 0;
  while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED))
  {
  	timedelay++;
	if(timedelay > I2C_DELAY_TIME)return;
  }
  
  /* While there is data to be read */
  while(NumByteToRead)  
  {
    if(NumByteToRead == 1)
    {
      /*失能应答*/
      I2C_AcknowledgeConfig(I2C1, DISABLE);
      
      /* Send STOP Condition */
      I2C_GenerateSTOP(I2C1, ENABLE);
    }

    /* Test on EV7 and clear it */
    if(I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED))  
    {      
      /* Read a byte from the EEPROM */
      *pBuffer = I2C_ReceiveData(I2C1);

      /* Point to the next location where the byte read will be saved */
      pBuffer++; 
      
      /* Decrement the read bytes counter */
      NumByteToRead--;        
    }   
  }

  /* Enable Acknowledgement to be ready for another reception */
  I2C_AcknowledgeConfig(I2C1, ENABLE);
}

/******************************************************************************
* Function Name  : I2C_EE_WaitEepromStandbyState
* Description    : 等待EEPROM的准备状态
* Input			 : None
******************************************************************************/
void I2C_EE_WaitEepromStandbyState(void)  
{
  vu16 SR1_Tmp = 0;

  do
  {
    /*发送开始条件*/
    I2C_GenerateSTART(I2C1, ENABLE);
    
	/*读取I2C1的状态寄存器1状态*/
    SR1_Tmp = I2C_ReadRegister(I2C1, I2C_Register_SR1);
    
	/*为写发送EEPROM写地址*/
    I2C_Send7bitAddress(I2C1, EEPROM_ADDRESS, I2C_Direction_Transmitter);
  }
  while(!(I2C_ReadRegister(I2C1, I2C_Register_SR1) & 0x0002));
  
  /*清应答错误标志位*/
  I2C_ClearFlag(I2C1, I2C_FLAG_AF);
    
  /*产生停止条件*/    
  I2C_GenerateSTOP(I2C1, ENABLE); 
}