[BUG] DAC software trigger at STM32L431 have not set DAC_SWTRIGR_SWTRIGx Bit.

[Wshuo.1]

My last page is: Re: Why DAC output nothing in software trigger? - STMicroelectronics Community

I have find CubeMX BUG.

I use STM32L431RCT6 and software version is STM32CubeL4 Firmware Package V1.18.0 / 07-June-2023

My STM32CubeMX config is:

And my code in main() is:

HAL_DAC_SetValue(&hdac1, DAC_CHANNEL_2, DAC_ALIGN_12B_R, 4095);
HAL_DAC_Start(&hdac1, DAC_CHANNEL_2);

But the PA5 have no voltage.

I find the "stm32l4xx_hal_dac.c" file HAL_DAC_Start() function is:

HAL_StatusTypeDef HAL_DAC_Start(DAC_HandleTypeDef *hdac, uint32_t Channel)
{
  /* Check the parameters */
  assert_param(IS_DAC_CHANNEL(Channel));

  /* Process locked */
  __HAL_LOCK(hdac);

  /* Change DAC state */
  hdac->State = HAL_DAC_STATE_BUSY;

  /* Enable the Peripheral */
  __HAL_DAC_ENABLE(hdac, Channel);

#if defined (STM32L4P5xx) || defined (STM32L4Q5xx) || defined (STM32L4R5xx) || defined (STM32L4R7xx) || defined (STM32L4R9xx) || defined (STM32L4S5xx) || defined (STM32L4S7xx) || defined(STM32L4S9xx)
  if (Channel == DAC_CHANNEL_1)
  {
    /* Check if software trigger enabled */
    if ((hdac->Instance->CR & (DAC_CR_TEN1 | DAC_CR_TSEL1)) == DAC_TRIGGER_SOFTWARE)
    {
      /* Enable the selected DAC software conversion */
      SET_BIT(hdac->Instance->SWTRIGR, DAC_SWTRIGR_SWTRIG1);
    }
  }
  else
  {
    /* Check if software trigger enabled */
    if ((hdac->Instance->CR & (DAC_CR_TEN2 | DAC_CR_TSEL2)) == (DAC_TRIGGER_SOFTWARE << (Channel & 0x10UL)))
    {
      /* Enable the selected DAC software conversion*/
      SET_BIT(hdac->Instance->SWTRIGR, DAC_SWTRIGR_SWTRIG2);
    }
  }

#endif /* STM32L4P5xx STM32L4Q5xx STM32L4R5xx STM32L4R7xx STM32L4R9xx STM32L4S5xx STM32L4S7xx STM32L4S9xx                                     */

#if defined (STM32L431xx) || defined (STM32L432xx) || defined (STM32L433xx) || defined (STM32L442xx) || defined (STM32L443xx) || \
    defined (STM32L471xx) || defined (STM32L475xx) || defined (STM32L476xx) || defined (STM32L485xx) || defined (STM32L486xx) || defined (STM32L496xx) || defined (STM32L4A6xx)
  if(Channel == DAC_CHANNEL_1)
  {
    /* Check if software trigger enabled */
    if ((hdac->Instance->CR & (DAC_CR_TEN1 | DAC_CR_TSEL1)) == DAC_CR_TEN1)
    {
      /* Enable the selected DAC software conversion */
      SET_BIT(hdac->Instance->SWTRIGR, DAC_SWTRIGR_SWTRIG1);
    }
  }
  else
  {
    /* Check if software trigger enabled */
    if ((hdac->Instance->CR & (DAC_CR_TEN2 | DAC_CR_TSEL2)) == DAC_CR_TEN2)
    {
      /* Enable the selected DAC software conversion*/
      SET_BIT(hdac->Instance->SWTRIGR, DAC_SWTRIGR_SWTRIG2);
    }
  }
#endif  /* STM32L431xx STM32L432xx STM32L433xx STM32L442xx STM32L443xx                         */
        /* STM32L471xx STM32L475xx STM32L476xx STM32L485xx STM32L486xx STM32L496xx STM32L4A6xx */


#if defined (STM32L451xx) || defined (STM32L452xx) || defined (STM32L462xx)
  /* Check if software trigger enabled */
  if((hdac->Instance->CR & (DAC_CR_TEN1 | DAC_CR_TSEL1)) == (DAC_CR_TEN1 | DAC_CR_TSEL1))
  {
    /* Enable the selected DAC software conversion */
    SET_BIT(hdac->Instance->SWTRIGR, DAC_SWTRIGR_SWTRIG1);
  }
#endif /* STM32L451xx STM32L452xx STM32L462xx */
  /* Change DAC state */
  hdac->State = HAL_DAC_STATE_READY;

  /* Process unlocked */
  __HAL_UNLOCK(hdac);

  /* Return function status */
  return HAL_OK;
}

 But in rm0394-stm32l41xxx42xxx43xxx44xxx45xxx46xxx-advanced-armbased-32bit-mcus-stmicroelectronics.pdf the TSELx config 0b111 with SWTRIG:

SO the code in check if software trigger enabled have error:

#if defined (STM32L431xx) || defined (STM32L432xx) || defined (STM32L433xx) || defined (STM32L442xx) || defined (STM32L443xx) || \
    defined (STM32L471xx) || defined (STM32L475xx) || defined (STM32L476xx) || defined (STM32L485xx) || defined (STM32L486xx) || defined (STM32L496xx) || defined (STM32L4A6xx)
  if(Channel == DAC_CHANNEL_1)
  {
    /* Check if software trigger enabled */
    if ((hdac->Instance->CR & (DAC_CR_TEN1 | DAC_CR_TSEL1)) == DAC_CR_TEN1)
    {
      /* Enable the selected DAC software conversion */
      SET_BIT(hdac->Instance->SWTRIGR, DAC_SWTRIGR_SWTRIG1);
    }
  }
  else
  {
    /* Check if software trigger enabled */
    if ((hdac->Instance->CR & (DAC_CR_TEN2 | DAC_CR_TSEL2)) == DAC_CR_TEN2)
    {
      /* Enable the selected DAC software conversion*/
      SET_BIT(hdac->Instance->SWTRIGR, DAC_SWTRIGR_SWTRIG2);
    }
  }
#endif  /* STM32L431xx STM32L432xx STM32L433xx STM32L442xx STM32L443xx                         */
        /* STM32L471xx STM32L475xx STM32L476xx STM32L485xx STM32L486xx STM32L496xx STM32L4A6xx */

Need change with:

#if defined (STM32L431xx) || defined (STM32L432xx) || defined (STM32L433xx) || defined (STM32L442xx) || defined (STM32L443xx) || \
    defined (STM32L471xx) || defined (STM32L475xx) || defined (STM32L476xx) || defined (STM32L485xx) || defined (STM32L486xx) || defined (STM32L496xx) || defined (STM32L4A6xx)
  if(Channel == DAC_CHANNEL_1)
  {
    /* Check if software trigger enabled */
    if ((hdac->Instance->CR & (DAC_CR_TEN1 | DAC_CR_TSEL1)) == (DAC_CR_TEN1 | DAC_CR_TSEL1)) {
      /* Enable the selected DAC software conversion */
      SET_BIT(hdac->Instance->SWTRIGR, DAC_SWTRIGR_SWTRIG1);
    }
  }
  else
  {
    /* Check if software trigger enabled */
    if ((hdac->Instance->CR & (DAC_CR_TEN2 | DAC_CR_TSEL2)) == (DAC_CR_TEN2 | DAC_CR_TSEL2)) {
      /* Enable the selected DAC software conversion*/
      SET_BIT(hdac->Instance->SWTRIGR, DAC_SWTRIGR_SWTRIG2);
    }
  }
#endif  /* STM32L431xx STM32L432xx STM32L433xx STM32L442xx STM32L443xx                         */
        /* STM32L471xx STM32L475xx STM32L476xx STM32L485xx STM32L486xx STM32L496xx STM32L4A6xx */

So the PA5 have voltage.

I only test STM32L431RCT6.

[Amel NASRI]

Hi @Wshuo.1 ,

Thank you and @waclawek.jan for bringing this issue to our attention.

I reported it internally to be fixed by our development team.

Internal ticket number: 191791 (This is an internal tracking number and is not accessible or usable by customers).

-Amel