Is this a bug that STM32H743 HAL_ADC_Stop_DMA clears ADC_CFGR_DMNGT?

[Aaron Chang]

Posted on August 21, 2017 at 11:48

Hello,

    In the line 1760 of 'stm32h7xx_hal_adc.c' in pack 'STM32H7xx_DFP 1.0.1':

'''

   /* Disable ADC DMA (ADC DMA configuration ADC_CFGR_DMNGT is kept) */

   MODIFY_REG(hadc->Instance->CFGR, ADC_CFGR_DMNGT_0 |ADC_CFGR_DMNGT_1, 0);

'''

    The comment says 'keep the DMNGT' while the code actually clears it.  Besides 

it doesn't make much sense to me that calling a 'HAL_ADC_Stop_DMA' could change the initial configuration of ADC.

    Is this a bug?  Or 'HAL_ADC_Stop_DMA' is not something I should call under normal condition?

[Amel NASRI]

Posted on August 23, 2017 at 18:02

Hi

aaron_chang

‌,

It seems the comment 'Disable ADC DMA (ADC DMA configuration ADC_CFGR_DMNGT is kept)' creates confusion for you.

In fact here,ADC_CFGR_DMNGT have to be cleared because the call ofADC_ConversionStop doesn't clear them: they are kept as they are.

So this is not a bug.

HAL_ADC_Stop_DMA may be useful in an application where ADC configuration needs to be modified for example to start with a new mode.

-Amel