}
  else
  {
    /* Get the Rx CRC register */
    crcreg = SPIx->RXCRCR;
  }
  /* Return the selected CRC register */
  return crcreg;
}

/**
  * @brief  Returns the CRC Polynomial register value for the specified SPI.
  * @param  SPIx: where x can be 1, 2 or 3 to select the SPI peripheral.
  * @retval The CRC Polynomial register value.
  */
uint16_t SPI_GetCRCPolynomial(SPI_TypeDef* SPIx)
{
  /* Check the parameters */
  assert_param(IS_SPI_ALL_PERIPH(SPIx));
  
  /* Return the CRC polynomial register */
  return SPIx->CRCPR;
}

/**
  * @}
  */

/** @defgroup SPI_Group4 DMA transfers management functions
 *  @brief   DMA transfers management functions
  *
@verbatim
 ===============================================================================
                ##### DMA transfers management functions #####
 ===============================================================================

@endverbatim
  * @{
  */

/**
  * @brief  Enables or disables the SPIx/I2Sx DMA interface.
  * @param  SPIx: To select the SPIx/I2Sx peripheral, where x can be: 1, 2 or 3 
  *               in SPI mode or 2 or 3 in I2S mode.
  * @param  SPI_I2S_DMAReq: specifies the SPI DMA transfer request to be enabled or disabled. 
  *   This parameter can be any combination of the following values:
  *     @arg SPI_I2S_DMAReq_Tx: Tx buffer DMA transfer request.
  *     @arg SPI_I2S_DMAReq_Rx: Rx buffer DMA transfer request.
  * @param  NewState: new state of the selected SPI DMA transfer request.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void SPI_I2S_DMACmd(SPI_TypeDef* SPIx, uint16_t SPI_I2S_DMAReq, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_SPI_ALL_PERIPH(SPIx));
  assert_param(IS_FUNCTIONAL_STATE(NewState));
  assert_param(IS_SPI_I2S_DMAREQ(SPI_I2S_DMAReq));

  if (NewState != DISABLE)
  {
    /* Enable the selected SPI DMA requests */
    SPIx->CR2 |= SPI_I2S_DMAReq;
  }
  else
  {
    /* Disable the selected SPI DMA requests */
    SPIx->CR2 &= (uint16_t)~SPI_I2S_DMAReq;
  }
}

/**
  * @}
  */

/** @defgroup SPI_Group5 Interrupts and flags management functions
 *  @brief   Interrupts and flags management functions
  *
@verbatim
 ===============================================================================
             ##### Interrupts and flags management functions #####
 ===============================================================================
    [..] This section provides a set of functions allowing to configure the SPI 
         Interrupts sources and check or clear the flags or pending bits status.
         The user should identify which mode will be used in his application to 
         manage the communication: Polling mode, Interrupt mode or DMA mode.
  *** Polling Mode ***
  ====================
    [..] In Polling Mode, the SPI/I2S communication can be managed by 9 flags:
        (#) SPI_I2S_FLAG_TXE : to indicate the status of the transmit buffer 
             register.
        (#) SPI_I2S_FLAG_RXNE : to indicate the status of the receive buffer 
             register.
        (#) SPI_I2S_FLAG_BSY : to indicate the state of the communication layer 
             of the SPI.
        (#) SPI_FLAG_CRCERR : to indicate if a CRC Calculation error occur.
        (#) SPI_FLAG_MODF : to indicate if a Mode Fault error occur.
        (#) SPI_I2S_FLAG_OVR : to indicate if an Overrun error occur.
        (#) SPI_I2S_FLAG_FRE: to indicate a Frame Format error occurs.
        (#) I2S_FLAG_UDR: to indicate an Underrun error occurs.
        (#) I2S_FLAG_CHSIDE: to indicate Channel Side.
    -@- Do not use the BSY flag to handle each data transmission or reception.
        It is better to use the TXE and RXNE flags instead.
    [..] In this Mode it is advised to use the following functions:
         (+) FlagStatus SPI_I2S_GetFlagStatus(SPI_TypeDef* SPIx, uint16_t SPI_I2S_FLAG).
         (+) void SPI_I2S_ClearFlag(SPI_TypeDef* SPIx, uint16_t SPI_I2S_FLAG).

  *** Interrupt Mode ***
  ======================
    [..] In Interrupt Mode, the SPI communication can be managed by 3 interrupt 
         sources and 7 pending bits: 
    [..] Pending Bits:
        (#) SPI_I2S_IT_TXE : to indicate the status of the transmit buffer register.
        (#) SPI_I2S_IT_RXNE : to indicate the status of the receive buffer register.
        (#) SPI_IT_CRCERR : to indicate if a CRC Calculation error occur.
        (#) SPI_IT_MODF : to indicate if a Mode Fault error occur.
        (#) SPI_I2S_IT_OVR : to indicate if an Overrun error occur.
        (#) I2S_IT_UDR : to indicate an Underrun Error occurs.
        (#) SPI_I2S_FLAG_FRE : to indicate a Frame Format error occurs.
    [..] Interrupt Source:
        (#) SPI_I2S_IT_TXE: specifies the interrupt source for the Tx buffer empty 
            interrupt.
        (#) SPI_I2S_IT_RXNE : specifies the interrupt source for the Rx buffer not 
            empty interrupt.
        (#) SPI_I2S_IT_ERR : specifies the interrupt source for the errors interrupt.
    [..] In this Mode it is advised to use the following functions:
         (+) void SPI_I2S_ITConfig(SPI_TypeDef* SPIx, uint8_t SPI_I2S_IT,
             FunctionalState NewState).
         (+) ITStatus SPI_I2S_GetITStatus(SPI_TypeDef* SPIx, uint8_t SPI_I2S_IT).
         (+) void SPI_I2S_ClearITPendingBit(SPI_TypeDef* SPIx, uint8_t SPI_I2S_IT).

  *** DMA Mode ***
  ================
    [..] In DMA Mode, the SPI communication can be managed by 2 DMA Channel 
         requests:
        (#) SPI_I2S_DMAReq_Tx: specifies the Tx buffer DMA transfer request.
        (#) SPI_I2S_DMAReq_Rx: specifies the Rx buffer DMA transfer request.

    [..] In this Mode it is advised to use the following function:
         (+) void SPI_I2S_DMACmd(SPI_TypeDef* SPIx, uint16_t SPI_I2S_DMAReq,
             FunctionalState NewState).

@endverbatim
  * @{
  */

/**
  * @brief  Enables or disables the specified SPI/I2S interrupts.
  * @param  SPIx: To select the SPIx/I2Sx peripheral, where x can be: 1, 2 or 3 
  *         in SPI mode or 2 or 3 in I2S mode.

  * @param  SPI_I2S_IT: specifies the SPI interrupt source to be enabled or disabled. 
  *   This parameter can be one of the following values:
  *     @arg SPI_I2S_IT_TXE: Tx buffer empty interrupt mask.
  *     @arg SPI_I2S_IT_RXNE: Rx buffer not empty interrupt mask.
  *     @arg SPI_I2S_IT_ERR: Error interrupt mask.
  * @param  NewState: new state of the specified SPI interrupt.
  *   This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void SPI_I2S_ITConfig(SPI_TypeDef* SPIx, uint8_t SPI_I2S_IT, FunctionalState NewState)
{
  uint16_t itpos = 0, itmask = 0 ;
  
  /* Check the parameters */
  assert_param(IS_SPI_ALL_PERIPH(SPIx));
  assert_param(IS_FUNCTIONAL_STATE(NewState));
  assert_param(IS_SPI_I2S_CONFIG_IT(SPI_I2S_IT));

  /* Get the SPI IT index */
  itpos = SPI_I2S_IT >> 4;

  /* Set the IT mask */
  itmask = (uint16_t)1 << (uint16_t)itpos;

  if (NewState != DISABLE)
  {
    /* Enable the selected SPI interrupt */
    SPIx->CR2 |= itmask;
  }
  else
  {
    /* Disable the selected SPI interrupt */
    SPIx->CR2 &= (uint16_t)~itmask;
  }
}

/**
  * @brief  Checks whether the specified SPIx/I2Sx flag is set or not.
  * @param  SPIx: To select the SPIx/I2Sx peripheral, where x can be: 1, 2 or 3 
  *         in SPI mode or 2 or 3 in I2S mode.

  * @param  SPI_I2S_FLAG: specifies the SPI flag to check. 
  *   This parameter can be one of the following values:
  *     @arg SPI_I2S_FLAG_TXE: Transmit buffer empty flag.
  *     @arg SPI_I2S_FLAG_RXNE: Receive buffer not empty flag.
  *     @arg SPI_I2S_FLAG_BSY: Busy flag.
  *     @arg SPI_I2S_FLAG_OVR: Overrun flag.
  *     @arg SPI_FLAG_MODF: Mode Fault flag.
  *     @arg SPI_FLAG_CRCERR: CRC Error flag.
  *     @arg SPI_I2S_FLAG_FRE: Format Error.
  *     @arg I2S_FLAG_UDR: Underrun Error flag.
  *     @arg I2S_FLAG_CHSIDE: Channel Side flag.
  * @retval The new state of SPI_I2S_FLAG (SET or RESET).
  */
FlagStatus SPI_I2S_GetFlagStatus(SPI_TypeDef* SPIx, uint16_t SPI_I2S_FLAG)
{
  FlagStatus bitstatus = RESET;
  /* Check the parameters */
  assert_param(IS_SPI_ALL_PERIPH(SPIx));
  assert_param(IS_SPI_I2S_GET_FLAG(SPI_I2S_FLAG));
  
  /* Check the status of the specified SPI flag */
  if ((SPIx->SR & SPI_I2S_FLAG) != (uint16_t)RESET)
  {
    /* SPI_I2S_FLAG is set */
    bitstatus = SET;
  }
  else
  {
    /* SPI_I2S_FLAG is reset */
    bitstatus = RESET;
  }
  /* Return the SPI_I2S_FLAG status */
  return  bitstatus;
}

/**
  * @brief  Clears the SPIx CRC Error (CRCERR) flag.
  * @param  SPIx: To select the SPIx/I2Sx peripheral, where x can be: 1, 2 or 3 
  *         in SPI mode or 2 or 3 in I2S mode.

  * @param  SPI_I2S_FLAG: specifies the SPI flag to clear. 
  *   This function clears only CRCERR flag.

  * @note OVR (OverRun error) flag is cleared by software sequence: a read 
  *     operation to SPI_DR register (SPI_I2S_ReceiveData()) followed by a read 
  *     operation to SPI_SR register (SPI_I2S_GetFlagStatus()).
  * @note UDR (UnderRun error) flag is cleared by a read operation to 
  *     SPI_SR register (SPI_I2S_GetFlagStatus()).   
  * @note MODF (Mode Fault) flag is cleared by software sequence: a read/write 
  *     operation to SPI_SR register (SPI_I2S_GetFlagStatus()) followed by a 
  *     write operation to SPI_CR1 register (SPI_Cmd() to enable the SPI).
  * @retval None
  */
void SPI_I2S_ClearFlag(SPI_TypeDef* SPIx, uint16_t SPI_I2S_FLAG)
{
  /* Check the parameters */
  assert_param(IS_SPI_ALL_PERIPH(SPIx));
  assert_param(IS_SPI_I2S_CLEAR_FLAG(SPI_I2S_FLAG));
    
  /* Clear the selected SPI CRC Error (CRCERR) flag */
  SPIx->SR = (uint16_t)~SPI_I2S_FLAG;
}

/**
  * @brief  Checks whether the specified SPIx/I2Sx interrupt has occurred or not.
  * @param  SPIx: To select the SPIx/I2Sx peripheral, where x can be: 1, 2 or 3 
  *         in SPI mode or 2 or 3 in I2S mode.

  * @param  SPI_I2S_IT: specifies the SPI interrupt source to check. 
  *   This parameter can be one of the following values:
  *     @arg SPI_I2S_IT_TXE: Transmit buffer empty interrupt.
  *     @arg SPI_I2S_IT_RXNE: Receive buffer not empty interrupt.
  *     @arg SPI_I2S_IT_OVR: Overrun interrupt.
  *     @arg SPI_IT_MODF: Mode Fault interrupt.
  *     @arg SPI_IT_CRCERR: CRC Error interrupt.
  *     @arg I2S_IT_UDR: Underrun interrupt.  
  *     @arg SPI_I2S_IT_FRE: Format Error interrupt.  
  * @retval The new state of SPI_I2S_IT (SET or RESET).
  */
ITStatus SPI_I2S_GetITStatus(SPI_TypeDef* SPIx, uint8_t SPI_I2S_IT)
{
  ITStatus bitstatus = RESET;
  uint16_t itpos = 0, itmask = 0, enablestatus = 0;

  /* Check the parameters */
  assert_param(IS_SPI_ALL_PERIPH(SPIx));
  assert_param(IS_SPI_I2S_GET_IT(SPI_I2S_IT));

  /* Get the SPI_I2S_IT index */
  itpos = 0x01 << (SPI_I2S_IT & 0x0F);

  /* Get the SPI_I2S_IT IT mask */
  itmask = SPI_I2S_IT >> 4;

  /* Set the IT mask */
  itmask = 0x01 << itmask;

  /* Get the SPI_I2S_IT enable bit status */
  enablestatus = (SPIx->CR2 & itmask) ;

  /* Check the status of the specified SPI interrupt */
  if (((SPIx->SR & itpos) != (uint16_t)RESET) && enablestatus)
  {
    /* SPI_I2S_IT is set */
    bitstatus = SET;
  }
  else
  {
    /* SPI_I2S_IT is reset */
    bitstatus = RESET;
  }
  /* Return the SPI_I2S_IT status */
  return bitstatus;
}

/**
  * @brief  Clears the SPIx CRC Error (CRCERR) interrupt pending bit.
  * @param  SPIx: To select the SPIx/I2Sx peripheral, where x can be: 1, 2 or 3 
  *         in SPI mode or 2 or 3 in I2S mode.

  * @param  SPI_I2S_IT: specifies the SPI interrupt pending bit to clear.
  *   This function clears only CRCERR interrupt pending bit.   

  *     OVR (OverRun Error) interrupt pending bit is cleared by software 
  *     sequence: a read operation to SPI_DR register (SPI_I2S_ReceiveData()) 
  *     followed by a read operation to SPI_SR register (SPI_I2S_GetITStatus()).
  * @note UDR (UnderRun Error) interrupt pending bit is cleared by a read 
  *     operation to SPI_SR register (SPI_I2S_GetITStatus()).   
  * @note MODF (Mode Fault) interrupt pending bit is cleared by software sequence:
  *     a read/write operation to SPI_SR register (SPI_I2S_GetITStatus()) 
  *     followed by a write operation to SPI_CR1 register (SPI_Cmd() to enable 
  *     the SPI).
  * @retval None
  */
void SPI_I2S_ClearITPendingBit(SPI_TypeDef* SPIx, uint8_t SPI_I2S_IT)
{
  uint16_t itpos = 0;
  /* Check the parameters */
  assert_param(IS_SPI_ALL_PERIPH(SPIx));
  assert_param(IS_SPI_I2S_CLEAR_IT(SPI_I2S_IT));

  /* Get the SPI_I2S IT index */
  itpos = 0x01 << (SPI_I2S_IT & 0x0F);

  /* Clear the selected SPI CRC Error (CRCERR) interrupt pending bit */
  SPIx->SR = (uint16_t)~itpos;
}

/**
  * @}
  */

/**
  * @}
  */ 

/**
  * @}
  */ 

/**
  * @}
  */ 

/******************* (C) COPYRIGHT 2012 STMicroelectronics *****END OF FILE****/