ADC with DMA in scan mode is not resulting in call to HAL_ADC_ConvCpltCallback

[GreenGuy]

Given:

STM32CubeIDE:

Version: 1.14.1

Build: 20064_20240111_1413 (UTC)

STM32CubeMX:

Version: 6.10.0-RC9

Build: 20231120-2037 (UTC)

OS:

Linux Lmint21

Initialization Code in Main for ADC: Scanning three internal values

static void MX_ADC3_Init(void)

{


/* USER CODE BEGIN ADC3_Init 0 */


/* USER CODE END ADC3_Init 0 */


ADC_ChannelConfTypeDef sConfig = {0};


/* USER CODE BEGIN ADC3_Init 1 */

 hadc3.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV1;

/* USER CODE END ADC3_Init 1 */


/** Common config

 */

 hadc3.Instance = ADC3;

 hadc3.Init.Resolution = ADC_RESOLUTION_16B;

 hadc3.Init.ScanConvMode = ADC_SCAN_ENABLE;

 hadc3.Init.EOCSelection = ADC_EOC_SEQ_CONV;

 hadc3.Init.LowPowerAutoWait = DISABLE;

 hadc3.Init.ContinuousConvMode = DISABLE;

 hadc3.Init.NbrOfConversion = 3;

 hadc3.Init.DiscontinuousConvMode = DISABLE;

 hadc3.Init.ExternalTrigConv = ADC_SOFTWARE_START;

 hadc3.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;

 hadc3.Init.ConversionDataManagement = ADC_CONVERSIONDATA_DMA_CIRCULAR;

 hadc3.Init.Overrun = ADC_OVR_DATA_PRESERVED;

 hadc3.Init.LeftBitShift = ADC_LEFTBITSHIFT_NONE;

 hadc3.Init.OversamplingMode = DISABLE;

if (HAL_ADC_Init(&hadc3) != HAL_OK)

 {

 Error_Handler();

 }


/** Configure Regular Channel

 */

 sConfig.Channel = ADC_CHANNEL_TEMPSENSOR;

 sConfig.Rank = ADC_REGULAR_RANK_1;

 sConfig.SamplingTime = ADC_SAMPLETIME_16CYCLES_5;

 sConfig.SingleDiff = ADC_SINGLE_ENDED;

 sConfig.OffsetNumber = ADC_OFFSET_NONE;

 sConfig.Offset = 0;

 sConfig.OffsetSignedSaturation = DISABLE;

if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK)

 {

 Error_Handler();

 }


/** Configure Regular Channel

 */

 sConfig.Channel = ADC_CHANNEL_VBAT;

 sConfig.Rank = ADC_REGULAR_RANK_2;

if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK)

 {

 Error_Handler();

 }


/** Configure Regular Channel

 */

 sConfig.Rank = ADC_REGULAR_RANK_3;

if (HAL_ADC_ConfigChannel(&hadc3, &sConfig) != HAL_OK)

 {

 Error_Handler();

 }

/* USER CODE BEGIN ADC3_Init 2 */

/* USER CODE END ADC3_Init 2 */
}

Note: I had to add the clock pre-scale to the beginning user code since this is still not available to select in CubeMX.

The system clock config is set to pass 50MHz to the ADC,

I did verify the ADC clock was being set in HAL_ADC_MspInit()

void HAL_ADC_MspInit(ADC_HandleTypeDef* hadc)
{
  if(hadc->Instance==ADC3)
  {
  /* USER CODE BEGIN ADC3_MspInit 0 */

  /* USER CODE END ADC3_MspInit 0 */
    /* Peripheral clock enable */
    __HAL_RCC_ADC3_CLK_ENABLE();

The code to perform the scan is in a thread (AZURE RTOS):

typedef struct ADCvalues{
	uint16_t Raw[3];
	double IntSensTmp;
	double int_ref;
	double vbat;
} adcval_t;

adcval_t ADC;

void ADC_Thread_entry(ULONG thread_input)
{
	(void) thread_input;

	tx_thread_sleep(500);
	HAL_ADC_Start_DMA(&hadc3, (uint32_t*)ADC.Raw, 3);

	while(1){
		tx_semaphore_get(&ADC_Semaphore, TX_WAIT_FOREVER);
		tx_thread_sleep(500);
		HAL_ADC_Start_DMA(&hadc3, (uint32_t*)ADC.Raw, 3);
	}
}

void HAL_ADC_ConvCpltCallback (ADC_HandleTypeDef *hadc)
{
	HAL_ADC_Stop_DMA(hadc);
	tx_semaphore_put(&ADC_Semaphore); // let system know the FPGA is done loading
}

and the interrupt handlers are in the stm32h7xx_it.c as:

void ADC3_IRQHandler(void)
{
  /* USER CODE BEGIN ADC3_IRQn 0 */

  /* USER CODE END ADC3_IRQn 0 */
  HAL_ADC_IRQHandler(&hadc3);
  /* USER CODE BEGIN ADC3_IRQn 1 */

  /* USER CODE END ADC3_IRQn 1 */
}

/**
  * @brief This function handles BDMA channel0 global interrupt.
  */
void BDMA_Channel0_IRQHandler(void)
{
  /* USER CODE BEGIN BDMA_Channel0_IRQn 0 */

  /* USER CODE END BDMA_Channel0_IRQn 0 */
  HAL_DMA_IRQHandler(&hdma_adc3);
  /* USER CODE BEGIN BDMA_Channel0_IRQn 1 */

  /* USER CODE END BDMA_Channel0_IRQn 1 */
}

The CubeMX Mode and params are set up as:

and

NVIC settings:

with DMA settings:

Also Register Callbacks are set to enable for ADC.

So what did I miss?

This did work a little as I was debugging and setting breakpoints. Pausing at the first HAL_ADC_Start_DMA call and stepping into the Hal code to verify parameters being passed, I then pushed play and hit the break point in the callback. However, continuing past the break point in the callback, I did not get anymore passes through the callback. Then, for reasons unknown this would not occur anymore after code changes that I cannot recall the sequence of. Now it does not work at all.

The code operation is intended to wait in the thread until a semaphore indicates a completed conversion. Then sleep for 5 seconds after which another conversion is started. There is no processing of the ADC values yet. I was going to add those later once I actually have data to process.

[GreenGuy]

I made a change that did not change any behavior.

I created a DTCM_section in the linker script and set the attribute of the ADC data structure to point to that section with:

__attribute__((section(".DTCMRAM_section"))) adcval_t ADC;

The debugger confirms the ADC structure is pointing to 0x20000000 (DTCM RAM).

Then I made another change that seems to have had some effect.  I changed the Overrun behavior to Overrun data overwritten.

Now, I hit the break points at the first call HAL_ADC_Start_DMA(&hadc3, (uint32_t*)ADC.Raw, 3); followed by the second call HAL_ADC_Start_DMA(&hadc3, (uint32_t*)ADC.Raw, 3); five seconds later in the while loop after the tx_semaphore_get.  But then, running the program further generates no more interrupts and hence no more hits to the HAL_ADC_ConvCpltCallback (ADC_HandleTypeDef *hadc) routine.

[SofLit · Accepted solution]

Hello, 

BDMA, DMA1 and DMA2 do not have access to the DTCM memory. BDMA has access to SRAM4 in D3 only. Please refer to the reference manual.

[GreenGuy]

Setting the DMA to DMA1 fixes the issue.  Thought I had tried this before and failed, but I must have had other issues in the setup.

Thank You SofLit