DMAy_Channelx->CNDTR = DMA_InitStruct->DMA_BufferSize;

/*--------------------------- DMAy Channelx CPAR Configuration ----------------*/
  /* Write to DMAy Channelx CPAR */
  DMAy_Channelx->CPAR = DMA_InitStruct->DMA_PeripheralBaseAddr;

/*--------------------------- DMAy Channelx CMAR Configuration ----------------*/
  /* Write to DMAy Channelx CMAR */
  DMAy_Channelx->CMAR = DMA_InitStruct->DMA_MemoryBaseAddr;
}

/**
  * @brief  Fills each DMA_InitStruct member with its default value.
  * @param  DMA_InitStruct: pointer to a DMA_InitTypeDef structure which will
  *         be initialized.
  * @retval None
  */
void DMA_StructInit(DMA_InitTypeDef* DMA_InitStruct)
{
/*-------------- Reset DMA init structure parameters values ------------------*/
  /* Initialize the DMA_PeripheralBaseAddr member */
  DMA_InitStruct->DMA_PeripheralBaseAddr = 0;
  /* Initialize the DMA_MemoryBaseAddr member */
  DMA_InitStruct->DMA_MemoryBaseAddr = 0;
  /* Initialize the DMA_DIR member */
  DMA_InitStruct->DMA_DIR = DMA_DIR_PeripheralSRC;
  /* Initialize the DMA_BufferSize member */
  DMA_InitStruct->DMA_BufferSize = 0;
  /* Initialize the DMA_PeripheralInc member */
  DMA_InitStruct->DMA_PeripheralInc = DMA_PeripheralInc_Disable;
  /* Initialize the DMA_MemoryInc member */
  DMA_InitStruct->DMA_MemoryInc = DMA_MemoryInc_Disable;
  /* Initialize the DMA_PeripheralDataSize member */
  DMA_InitStruct->DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
  /* Initialize the DMA_MemoryDataSize member */
  DMA_InitStruct->DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
  /* Initialize the DMA_Mode member */
  DMA_InitStruct->DMA_Mode = DMA_Mode_Normal;
  /* Initialize the DMA_Priority member */
  DMA_InitStruct->DMA_Priority = DMA_Priority_Low;
  /* Initialize the DMA_M2M member */
  DMA_InitStruct->DMA_M2M = DMA_M2M_Disable;
}

/**
  * @brief  Enables or disables the specified DMAy Channelx.
  * @param  DMAy_Channelx: where y can be 1 to select the DMA and
  *         x can be 1 to 7 for DMA1 to select the DMA Channel.
  * @param  NewState: new state of the DMAy Channelx. 
  *         This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void DMA_Cmd(DMA_Channel_TypeDef* DMAy_Channelx, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_DMA_ALL_PERIPH(DMAy_Channelx));
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)
  {
    /* Enable the selected DMAy Channelx */
    DMAy_Channelx->CCR |= DMA_CCR1_EN;
  }
  else
  {
    /* Disable the selected DMAy Channelx */
    DMAy_Channelx->CCR &= (uint16_t)(~DMA_CCR1_EN);
  }
}

/**
  * @}
  */

/** @defgroup DMA_Group2 Data Counter functions
 *  @brief   Data Counter functions 
 *
@verbatim   
 ===============================================================================
                           Data Counter functions
 ===============================================================================  

  This subsection provides function allowing to configure and read the buffer size
  (number of data to be transferred). 

  The DMA data counter can be written only when the DMA channel is disabled 
  (ie. after transfer complete event).

  The following function can be used to write the Channel data counter value:
    - void DMA_SetCurrDataCounter(DMA_Channel_TypeDef* DMAy_Channelx, uint16_t DataNumber);

@note It is advised to use this function rather than DMA_Init() in situations where
      only the Data buffer needs to be reloaded.

  The DMA data counter can be read to indicate the number of remaining transfers for
  the relative DMA channel. This counter is decremented at the end of each data 
  transfer and when the transfer is complete: 
   - If Normal mode is selected: the counter is set to 0.
   - If Circular mode is selected: the counter is reloaded with the initial value
     (configured before enabling the DMA channel)
   
  The following function can be used to read the Channel data counter value:
     - uint16_t DMA_GetCurrDataCounter(DMA_Channel_TypeDef* DMAy_Channelx);

@endverbatim
  * @{
  */

/**
  * @brief  Sets the number of data units in the current DMAy Channelx transfer.
  * @param  DMAy_Channelx: where y can be 1 to select the DMA and
  *         x can be 1 to 7 for DMA1 to select the DMA Channel.
  * @param  DataNumber: The number of data units in the current DMAy Channelx
  *         transfer.   
  * @note   This function can only be used when the DMAy_Channelx is disabled.                 
  * @retval None.
  */
void DMA_SetCurrDataCounter(DMA_Channel_TypeDef* DMAy_Channelx, uint16_t DataNumber)
{
  /* Check the parameters */
  assert_param(IS_DMA_ALL_PERIPH(DMAy_Channelx));
  
/*--------------------------- DMAy Channelx CNDTR Configuration ---------------*/
  /* Write to DMAy Channelx CNDTR */
  DMAy_Channelx->CNDTR = DataNumber;  
}

/**
  * @brief  Returns the number of remaining data units in the current
  *         DMAy Channelx transfer.
  * @param  DMAy_Channelx: where y can be 1 to select the DMA and
  *         x can be 1 to 7 for DMA1 to select the DMA Channel.
  * @retval The number of remaining data units in the current DMAy Channelx
  *         transfer.
  */
uint16_t DMA_GetCurrDataCounter(DMA_Channel_TypeDef* DMAy_Channelx)
{
  /* Check the parameters */
  assert_param(IS_DMA_ALL_PERIPH(DMAy_Channelx));
  /* Return the number of remaining data units for DMAy Channelx */
  return ((uint16_t)(DMAy_Channelx->CNDTR));
}

/**
  * @}
  */

/** @defgroup DMA_Group3 Interrupts and flags management functions
 *  @brief   Interrupts and flags management functions 
 *
@verbatim   
 ===============================================================================
                  Interrupts and flags management functions
 ===============================================================================  

  This subsection provides functions allowing to configure the DMA 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
  DMA controller events: Polling mode or Interrupt mode. 
    
  Polling Mode
  =============
    Each DMA channel can be managed through 4 event Flags:
    (y : DMA Controller number  
     x : DMA channel number )
       1. DMAy_FLAG_TCx : to indicate that a Transfer Complete event occurred
       2. DMAy_FLAG_HTx : to indicate that a Half-Transfer Complete event occured
       3. DMAy_FLAG_TEx : to indicate that a Transfer Error occured.
       4. DMAy_FLAG_GLx : to indicate that at least one of the events described 
          above occured.             

@note Clearing DMAy_FLAG_GLx results in clearing all other pending flags of the 
      same channel (DMAy_FLAG_TCx, DMAy_FLAG_HTx and DMAy_FLAG_TEx).

   In this Mode it is advised to use the following functions:
      - FlagStatus DMA_GetFlagStatus(uint32_t DMA_FLAG);
      - void DMA_ClearFlag(uint32_t DMA_FLAG);

  Interrupt Mode
  ===============
    Each DMA channel can be managed through 4 Interrupts:

    Interrupt Source
    ----------------
       1. DMA_IT_TC: specifies the interrupt source for the Transfer Complete event.  
       2. DMA_IT_HT : specifies the interrupt source for the Half-transfer Complete event.
       3. DMA_IT_TE : specifies the interrupt source for the transfer errors event.
       4. DMA_IT_GL : to indicate that at least one of the interrupts described 
          above occurred. 

@note Clearing DMA_IT_GL interrupt results in clearing all other interrupts of the 
      same channel (DMA_IT_TCx, DMA_IT_HT and DMA_IT_TE).
     
  In this Mode it is advised to use the following functions:
     - void DMA_ITConfig(DMA_Channel_TypeDef* DMAy_Channelx, uint32_t DMA_IT, FunctionalState NewState);
     - ITStatus DMA_GetITStatus(uint32_t DMA_IT);
     - void DMA_ClearITPendingBit(uint32_t DMA_IT);

@endverbatim
  * @{
  */

/**
  * @brief  Enables or disables the specified DMAy Channelx interrupts.
  * @param  DMAy_Channelx: where y can be 1 to select the DMA and
  *         x can be 1 to 7 for DMA1 to select the DMA Channel.
  * @param  DMA_IT: specifies the DMA interrupts sources to be enabled
  *         or disabled. 
  *   This parameter can be any combination of the following values:
  *     @arg DMA_IT_TC: Transfer complete interrupt mask
  *     @arg DMA_IT_HT: Half transfer interrupt mask
  *     @arg DMA_IT_TE: Transfer error interrupt mask
  * @param  NewState: new state of the specified DMA interrupts.
  *         This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void DMA_ITConfig(DMA_Channel_TypeDef* DMAy_Channelx, uint32_t DMA_IT, FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_DMA_ALL_PERIPH(DMAy_Channelx));
  assert_param(IS_DMA_CONFIG_IT(DMA_IT));
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  if (NewState != DISABLE)
  {
    /* Enable the selected DMA interrupts */
    DMAy_Channelx->CCR |= DMA_IT;
  }
  else
  {
    /* Disable the selected DMA interrupts */
    DMAy_Channelx->CCR &= ~DMA_IT;
  }
}

/**
  * @brief  Checks whether the specified DMAy Channelx flag is set or not.
  * @param  DMA_FLAG: specifies the flag to check.
  *   This parameter can be one of the following values:
  *     @arg DMA1_FLAG_GL1: DMA1 Channel1 global flag.
  *     @arg DMA1_FLAG_TC1: DMA1 Channel1 transfer complete flag.
  *     @arg DMA1_FLAG_HT1: DMA1 Channel1 half transfer flag.
  *     @arg DMA1_FLAG_TE1: DMA1 Channel1 transfer error flag.
  *     @arg DMA1_FLAG_GL2: DMA1 Channel2 global flag.
  *     @arg DMA1_FLAG_TC2: DMA1 Channel2 transfer complete flag.
  *     @arg DMA1_FLAG_HT2: DMA1 Channel2 half transfer flag.
  *     @arg DMA1_FLAG_TE2: DMA1 Channel2 transfer error flag.
  *     @arg DMA1_FLAG_GL3: DMA1 Channel3 global flag.
  *     @arg DMA1_FLAG_TC3: DMA1 Channel3 transfer complete flag.
  *     @arg DMA1_FLAG_HT3: DMA1 Channel3 half transfer flag.
  *     @arg DMA1_FLAG_TE3: DMA1 Channel3 transfer error flag.