75x_i2c.c

ST的ARM7芯片完整DEMO程序。 具备点阵液晶显示器

/*******************************************************************************
* Function Name  : I2C_ITConfig                                               
* Description    : Enables or disables the I2C interrupt.                 
* Input          : - NewState: new state of the I2C interrupt.
*                    This parameter can be: ENABLE or DISABLE.
* Output         : None                      
* Return         : None.                                                      
*******************************************************************************/
void I2C_ITConfig(FunctionalState NewState)
{
  if (NewState == ENABLE)
  {
    /* Enable the I2C interrupt */
    I2C->CR |= I2C_IT_Enable;
  }
  else
  {
    /* Disable the I2C interrupt */
    I2C->CR &= I2C_IT_Disable;
  }
}

/*******************************************************************************
* Function Name  : I2C_GetLastEvent                                  
* Description    : Gets the last I2C event that has occurred.                  
* Input          : None  
* Output         : None                          
* Return         : The Last happened Event.                           
*******************************************************************************/
u16 I2C_GetLastEvent(void)
{
  u16 Flag1 = 0, Flag2 = 0, LastEvent = 0;

  Flag1 = I2C->SR1;
  Flag2 = I2C->SR2;
  Flag2 = Flag2<<8;
  /* Get the last event value from I2C status register */
  LastEvent = (((Flag1 | (Flag2)) & I2C_Event_Mask));
  /* Return the last event */
  return LastEvent;
}

/*******************************************************************************
* Function Name  : I2C_CheckEvent                                         
* Description    : Checks whether the Last I2C Event is equal to the one passed 
*                  as parameter.                                              
* Input          : - I2C_EVENT: specifies the event to be checked. This parameter
*                    can be one of the following values:
*                         - I2C_EVENT_SLAVE_ADDRESS_MATCHED
*                         - I2C_EVENT_SLAVE_BYTE_RECEIVED
*                         - I2C_EVENT_SLAVE_BYTE_TRANSMITTED
*                         - I2C_EVENT_SLAVE_ACK_FAILURE 
*                         - I2C_EVENT_MASTER_MODE_SELECT
*                         - I2C_EVENT_MASTER_MODE_SELECTED
*                         - I2C_EVENT_MASTER_BYTE_RECEIVED
*                         - I2C_EVENT_MASTER_BYTE_TRANSMITTED
*                         - I2C_EVENT_MASTER_MODE_ADDRESS10
*                         - I2C_EVENT_SLAVE_STOP_DETECTED
* Output         : None                                      
* Return         : An ErrorStatus enumuration value:
*                         - SUCCESS: Last event is equal to the I2C_Event
*                         - ERROR: Last event is different from the I2C_Event        
*******************************************************************************/
ErrorStatus I2C_CheckEvent(u16 I2C_EVENT)
{
  u16  LastEvent = I2C_GetLastEvent();

  /* Check whether the last event is equal to I2C_EVENT */
  if (LastEvent == I2C_EVENT)
  {
    /* Return SUCCESS when last event is equal to I2C_EVENT */
    return SUCCESS;
  }
  else
  {
    /* Return ERROR when last event is different from I2C_EVENT */
    return ERROR;
  }
}

/*******************************************************************************
* Function Name  : I2C_SendData                                                
* Description    : Sends a data byte.                                 
* Input          : - Data: indicates the byte to be transmitted.
* Output         : None            
* Return         : None.                                                       
*******************************************************************************/
void I2C_SendData(u8 Data)
{
  /* Write in the DR register the byte to be sent */
  I2C->DR = Data;
}

/*******************************************************************************
* Function Name  : I2C_ReceiveData                                             
* Description    : Reads the received byte. 
* Input          : None 
* Output         : None                                        
* Return         : The received byte                                      
*******************************************************************************/
u8 I2C_ReceiveData(void)
{
  /* Return from the DR register the received byte */
  return I2C->DR;
}

/*******************************************************************************
* Function Name  : I2C_Send7bitAddress                                             
* Description    : Transmits the address byte to select the slave device.      
* Input          : - Address: specifies the slave address which will be transmitted    
*                  - Direction: specifies whether the I2C device will be a 
*                    Transmitter or a Receiver. This parameter can be one of the 
*                    following values
*                         - I2C_MODE_TRANSMITTER: Transmitter mode
*                         - I2C_MODE_RECEIVER: Receiver mode  
* Output         : None	
* Return         : None.                                                       
*******************************************************************************/
void I2C_Send7bitAddress(u8 Address, u8 Direction)
{
  /* Test on the direction to define the read/write bit */
  if (Direction == I2C_MODE_RECEIVER)
  {
    /* Set the address bit0 for read */
    Address |= I2C_ADD0_Set;
  }
  else
  {
    /* Reset the address bit0 for write */
    Address &= I2C_ADD0_Reset;
  }
  /* Send the address */
  I2C->DR = Address;
}

/*******************************************************************************
* Function Name  : I2C_ReadRegister                                            
* Description    : Reads the specified I2C register and returns its value.    
* Input1         : - I2C_Register: specifies the register to read.
*                    This parameter can be one of the following values:        
*                         - I2C_CR:   CR register. 
*                         - I2C_SR1:  SR1 register.
*                         - I2C_SR2:  SR2 register.
*                         - I2C_CCR:  CCR register.
*                         - I2C_OAR1: OAR1 register.
*                         - I2C_OAR2: OAR2 register.
*                         - I2C_DR:   DR register.
*                         - I2C_ECCR: ECCR register.
* Output         : None
* Return         : The value of the read register.              
*******************************************************************************/
u8 I2C_ReadRegister(u8 I2C_Register)
{
  /* Return the selected register value */
  return (*(u8 *)(I2C_BASE + I2C_Register));
}

/*******************************************************************************
* Function Name  : I2C_GetFlagStatus  
* Description    : Checks whether the specified I2C flag is set or not.
* Input          : - I2C_FLAG: specifies the flag to check. 
*                    This parameter can be one of the following values:
*                         - I2C_FLAG_SB: Start bit flag (Master mode)    
*                         - I2C_FLAG_M_SL: Master/Slave flag   
*                         - I2C_FLAG_ADSL: Address matched flag (Slave mode)    
*                         - I2C_FLAG_BTF: Byte transfer finished flag    
*                         - I2C_FLAG_BUSY: Bus busy flag    
*                         - I2C_FLAG_TRA: Transmitter/Receiver flag    
*                         - I2C_FLAG_ADD10: 10-bit addressing in Master mode flag   
*                         - I2C_FLAG_EVF: Event flag     
*                         - I2C_FLAG_GCAL: General call flag (slave mode)   
*                         - I2C_FLAG_BERR: Bus error flag    
*                         - I2C_FLAG_ARLO: Arbitration lost flag    
*                         - I2C_FLAG_STOPF: Stop detection flag (slave mode)   
*                         - I2C_FLAG_AF: Acknowledge failure flag      
*                         - I2C_FLAG_ENDAD: End of address transmission flag   
*                         - I2C_FLAG_ACK: Acknowledge enable flag     
* Output         : None                                                   
* Return         : The NewState of the I2C_FLAG (SET or RESET).              
*******************************************************************************/
FlagStatus I2C_GetFlagStatus(u16 I2C_FLAG)
{ 
    u16 Flag1 = 0, Flag2 = 0, Flag3 = 0, Tmp = 0;

  Flag1 = I2C->SR1;
  Flag2 = I2C->SR2;
  Flag2 = Flag2<<8;
  Flag3 = I2C->CR & 0x04;
  
  /* Get all the I2C flags in a unique register*/
  Tmp = (((Flag1 | (Flag2)) & I2C_Event_Mask) | (Flag3<<12)); 
  
  /* Check the status of the specified I2C flag */
  if((Tmp & I2C_FLAG) != RESET)
  {
    /* Return SET if I2C_FLAG is set */
    return SET;
  }
  else
  {
    /* Return RESET if I2C_FLAG is reset */
    return RESET;
  }
}

/*******************************************************************************
* Function Name  : I2C_ClearFlag                                 
* Description    : Clears the I2C抯 pending flags                            
* Input          : - I2C_FLAG: specifies the flag to clear. 
*                    This parameter can be one of the following values:
*                         - I2C_FLAG_SB: Start bit flag    
*                         - I2C_FLAG_M_SL: Master/Slave flag   
*                         - I2C_FLAG_ADSL: Adress matched flag    
*                         - I2C_FLAG_BTF: Byte transfer finished flag    
*                         - I2C_FLAG_BUSY: Bus busy flag    
*                         - I2C_FLAG_TRA: Transmitter/Receiver flag    
*                         - I2C_FLAG_ADD10: 10-bit addressing in Master mode flag   
*                         - I2C_FLAG_EVF: Event flag     
*                         - I2C_FLAG_GCAL: General call flag    
*                         - I2C_FLAG_BERR: Bus error flag    
*                         - I2C_FLAG_ARLO: Arbitration lost flag    
*                         - I2C_FLAG_STOPF: Stop detection flag   
*                         - I2C_FLAG_AF: Acknowledge failure flag      
*                         - I2C_FLAG_ENDAD: End of address transmission flag   
*                         - I2C_FLAG_ACK: Acknowledge enable flag             
*                  - parameter needed in the case that the flag to be cleared
*                    need a write in one register  
* Output         : None	                                             
* Return         : None                                                      
*******************************************************************************/
void I2C_ClearFlag(u16 I2C_FLAG, ...)
{
  u8 Tmp = (u8)*((u32 *) & I2C_FLAG + sizeof(I2C_FLAG));

  /* flags that need a read of the SR2 register to be cleared */
  if ((I2C_FLAG == I2C_FLAG_ADD10) || (I2C_FLAG == I2C_FLAG_EVF) ||
      (I2C_FLAG == I2C_FLAG_STOPF) || (I2C_FLAG == I2C_FLAG_AF)  || 
      (I2C_FLAG == I2C_FLAG_BERR) ||  (I2C_FLAG == I2C_FLAG_ARLO) ||
      (I2C_FLAG == I2C_FLAG_ENDAD))
  {
    /* Read the SR2 register */
    (void)I2C->SR2;

    /* Two flags need a second step to be cleared */
    switch (I2C_FLAG)
    {
       case  I2C_FLAG_ADD10:
         /* Send the MSB 10bit address passed as second parameter */
         I2C->DR = Tmp; 
         break;
       case  I2C_FLAG_ENDAD: 
         /* Write to the I2C_CR register by setting PE bit */
         I2C->CR |= I2C_PE_Set;
         break;
    }
  }
  /* flags that need a read of the SR1 register to be cleared */
  else if (I2C_FLAG==I2C_FLAG_SB || I2C_FLAG==I2C_FLAG_ADSL || I2C_FLAG==I2C_FLAG_BTF || I2C_FLAG==I2C_FLAG_TRA)
  {
    /* Read the SR1 register */
    (void)I2C->SR1;

    /* three flags need a second step to be cleared */
    if (I2C_FLAG == I2C_FLAG_SB)
    {
      /* Send the address byte passed as second parameter */
      I2C->DR=Tmp;
    }
    else if (I2C_FLAG==I2C_FLAG_BTF || I2C_FLAG==I2C_FLAG_TRA)
    {
      /* return the received byte in the variable passed as second parameter  */
      Tmp=I2C->DR;
    }
  }
  /* flags that need to disable the I2C interface */
  else if ( I2C_FLAG==I2C_FLAG_M_SL || I2C_FLAG==I2C_FLAG_GCAL)
  {
    I2C_Cmd(DISABLE);
    I2C_Cmd(ENABLE);
  }
}

/******************* (C) COPYRIGHT 2006 STMicroelectronics *****END OF FILE****/