Regular Channels DMA Configuration functions
[ADC_Private_Functions]

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            ##### Regular Channels DMA Configuration functions #####
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    [..] This section provides functions allowing to configure the DMA for ADC 
         regular channels.
         Since converted regular channel values are stored into a unique data 
         register, it is useful to use DMA for conversion of more than one regular 
         channel. This avoids the loss of the data already stored in the ADC 
         Data register.   
         When the DMA mode is enabled (using the ADC_DMACmd() function), after each
         conversion of a regular channel, a DMA request is generated.
    [..] Depending on the "DMA disable selection for Independent ADC mode" 
         configuration (using the ADC_DMARequestAfterLastTransferCmd() function), 
         at the end of the last DMA transfer, two possibilities are allowed:
      (+) No new DMA request is issued to the DMA controller (feature DISABLED) 
      (+) Requests can continue to be generated (feature ENABLED).  
    [..] Depending on the "DMA disable selection for multi ADC mode" configuration 
         (using the void ADC_MultiModeDMARequestAfterLastTransferCmd() function), 
         at the end of the last DMA transfer, two possibilities are allowed:
        (+) No new DMA request is issued to the DMA controller (feature DISABLED) 
        (+) Requests can continue to be generated (feature ENABLED).