STM32H732 I2S Unstable Clocks (Stutter)

[Gkatsos]

I have set up a project in STM32CubeMX.

I have setup both I2S1 for Receiving and I2S2 for Transmiting with DMA.

After the normal initalization i start receiving from the DMA:

if (HAL_I2S_Transmit_DMA(&hi2s2, (uint16_t*)&output_buffer, 1) != HAL_OK)
{
    Error_Handler();
}

And the setup of the I2S are as following:

void MX_I2S1_Init(void)
{
  hi2s1.Instance = SPI1;
  hi2s1.Init.Mode = I2S_MODE_MASTER_RX;
  hi2s1.Init.Standard = I2S_STANDARD_PHILIPS;
  hi2s1.Init.DataFormat = I2S_DATAFORMAT_32B;
  hi2s1.Init.MCLKOutput = I2S_MCLKOUTPUT_ENABLE;
  hi2s1.Init.AudioFreq = I2S_AUDIOFREQ_48K;
  hi2s1.Init.CPOL = I2S_CPOL_LOW;
  hi2s1.Init.FirstBit = I2S_FIRSTBIT_MSB;
  hi2s1.Init.WSInversion = I2S_WS_INVERSION_DISABLE;
  hi2s1.Init.Data24BitAlignment = I2S_DATA_24BIT_ALIGNMENT_LEFT;
  hi2s1.Init.MasterKeepIOState = I2S_MASTER_KEEP_IO_STATE_ENABLE;
  if (HAL_I2S_Init(&hi2s1) != HAL_OK)
  {
    Error_Handler();
  }
}

void MX_I2S2_Init(void)
{
  hi2s2.Instance = SPI2;
  hi2s2.Init.Mode = I2S_MODE_MASTER_TX;
  hi2s2.Init.Standard = I2S_STANDARD_PHILIPS;
  hi2s2.Init.DataFormat = I2S_DATAFORMAT_32B;
  hi2s2.Init.MCLKOutput = I2S_MCLKOUTPUT_ENABLE;
  hi2s2.Init.AudioFreq = I2S_AUDIOFREQ_48K;
  hi2s2.Init.CPOL = I2S_CPOL_LOW;
  hi2s2.Init.FirstBit = I2S_FIRSTBIT_MSB;
  hi2s2.Init.WSInversion = I2S_WS_INVERSION_DISABLE;
  hi2s2.Init.Data24BitAlignment = I2S_DATA_24BIT_ALIGNMENT_LEFT;
  hi2s2.Init.MasterKeepIOState = I2S_MASTER_KEEP_IO_STATE_DISABLE;
  if (HAL_I2S_Init(&hi2s2) != HAL_OK)
  {
    Error_Handler();
  }
}

The HAL_I2S_RxCpltCallback doesn't do anything right now and the I2S2 is not started with the DMA.

I am only using the MCLK, BCLK, and LRCLK, and have conneted the peripherals ADC and DAC to these and their DIN and DOUT are connected, so if MCLK, BCLK, and LRCLK I should have a clean connection, but the audio is choppy. I can see when measuring MCLK, BCLK, and LRCLK, their frequency sporadically go up, cutting the correct transfer, to then go back. The stuttering happens a few times per second.

I have spent a lot of time trying to fix this, but i have no idea how to fix it.

[MasterT]

Verify where main uCPU clock is coming from.  To have low jitter use crystal HSE. For nucleo boards ST-Link

[Gkatsos]

So here are my newest measurements, LRCLK (BLUE) and BCLK (YELLOW). The problem isn't jitter, but that LRCLK changes more often than every 32 BCLK, but only a few times per second.

[Gkatsos]

I am using the HSI, but as i have just added, it isn't jitter.

[MasterT]

What is the dma mode? Is it possible that 

HAL_I2S_Transmit_DMA

restarts happened?

Better to post all your code.

[Gkatsos]

The DMA mode is circular, so i don't expect any restarts, here is the rest of the I2S.c:

void HAL_I2S_MspInit(I2S_HandleTypeDef* i2sHandle)
{

  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(i2sHandle->Instance==SPI1)
  {
    /* I2S1 clock enable */
    __HAL_RCC_SPI1_CLK_ENABLE();

    __HAL_RCC_GPIOA_CLK_ENABLE();
    __HAL_RCC_GPIOC_CLK_ENABLE();
    /**I2S1 GPIO Configuration
    PA5     ------> I2S1_CK
    PA6     ------> I2S1_SDI
    PC4     ------> I2S1_MCK
    PA15(JTDI)     ------> I2S1_WS
    */
    GPIO_InitStruct.Pin = GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_15;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStruct.Alternate = GPIO_AF5_SPI1;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    GPIO_InitStruct.Pin = GPIO_PIN_4;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStruct.Alternate = GPIO_AF5_SPI1;
    HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

    /* I2S1 DMA Init */
    /* SPI1_RX Init */
    hdma_spi1_rx.Instance = DMA1_Stream0;
    hdma_spi1_rx.Init.Request = DMA_REQUEST_SPI1_RX;
    hdma_spi1_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
    hdma_spi1_rx.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_spi1_rx.Init.MemInc = DMA_MINC_ENABLE;
    hdma_spi1_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_WORD;
    hdma_spi1_rx.Init.MemDataAlignment = DMA_MDATAALIGN_WORD;
    hdma_spi1_rx.Init.Mode = DMA_CIRCULAR;
    hdma_spi1_rx.Init.Priority = DMA_PRIORITY_LOW;
    hdma_spi1_rx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
    if (HAL_DMA_Init(&hdma_spi1_rx) != HAL_OK)
    {
      Error_Handler();
    }

    __HAL_LINKDMA(i2sHandle,hdmarx,hdma_spi1_rx);

    /* I2S1 interrupt Init */
    HAL_NVIC_SetPriority(SPI1_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(SPI1_IRQn);
  }
  else if(i2sHandle->Instance==SPI2)
  {
    /* I2S2 clock enable */
    __HAL_RCC_SPI2_CLK_ENABLE();

    __HAL_RCC_GPIOC_CLK_ENABLE();
    __HAL_RCC_GPIOB_CLK_ENABLE();
    /**I2S2 GPIO Configuration
    PC1     ------> I2S2_SDO
    PB10     ------> I2S2_CK
    PB12     ------> I2S2_WS
    PC6     ------> I2S2_MCK
    */
    GPIO_InitStruct.Pin = GPIO_PIN_1|GPIO_PIN_6;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStruct.Alternate = GPIO_AF5_SPI2;
    HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

    GPIO_InitStruct.Pin = GPIO_PIN_10|GPIO_PIN_12;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStruct.Alternate = GPIO_AF5_SPI2;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

    /* I2S2 DMA Init */
    /* SPI2_TX Init */
    hdma_spi2_tx.Instance = DMA1_Stream1;
    hdma_spi2_tx.Init.Request = DMA_REQUEST_SPI2_TX;
    hdma_spi2_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
    hdma_spi2_tx.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_spi2_tx.Init.MemInc = DMA_MINC_ENABLE;
    hdma_spi2_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_WORD;
    hdma_spi2_tx.Init.MemDataAlignment = DMA_MDATAALIGN_WORD;
    hdma_spi2_tx.Init.Mode = DMA_CIRCULAR;
    hdma_spi2_tx.Init.Priority = DMA_PRIORITY_LOW;
    hdma_spi2_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
    if (HAL_DMA_Init(&hdma_spi2_tx) != HAL_OK)
    {
      Error_Handler();
    }

    __HAL_LINKDMA(i2sHandle,hdmatx,hdma_spi2_tx);

    /* I2S2 interrupt Init */
    HAL_NVIC_SetPriority(SPI2_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(SPI2_IRQn);
  }
}

void HAL_I2S_MspDeInit(I2S_HandleTypeDef* i2sHandle)
{
  if(i2sHandle->Instance==SPI1)
  {
    /* Peripheral clock disable */
    __HAL_RCC_SPI1_CLK_DISABLE();

    /**I2S1 GPIO Configuration
    PA5     ------> I2S1_CK
    PA6     ------> I2S1_SDI
    PC4     ------> I2S1_MCK
    PA15(JTDI)     ------> I2S1_WS
    */
    HAL_GPIO_DeInit(GPIOA, GPIO_PIN_5|GPIO_PIN_6|GPIO_PIN_15);

    HAL_GPIO_DeInit(GPIOC, GPIO_PIN_4);

    /* I2S1 DMA DeInit */
    HAL_DMA_DeInit(i2sHandle->hdmarx);

    /* I2S1 interrupt Deinit */
    HAL_NVIC_DisableIRQ(SPI1_IRQn);
  }
  else if(i2sHandle->Instance==SPI2)
  {
    /* Peripheral clock disable */
    __HAL_RCC_SPI2_CLK_DISABLE();

    /**I2S2 GPIO Configuration
    PC1     ------> I2S2_SDO
    PB10     ------> I2S2_CK
    PB12     ------> I2S2_WS
    PC6     ------> I2S2_MCK
    */
    HAL_GPIO_DeInit(GPIOC, GPIO_PIN_1|GPIO_PIN_6);

    HAL_GPIO_DeInit(GPIOB, GPIO_PIN_10|GPIO_PIN_12);

    /* I2S2 DMA DeInit */
    HAL_DMA_DeInit(i2sHandle->hdmatx);

    /* I2S2 interrupt Deinit */
    HAL_NVIC_DisableIRQ(SPI2_IRQn);
  }
}

[MasterT]

if (HAL_I2S_Transmit_DMA(&hi2s2, (uint16_t*)&output_buffer, 1) != HAL_OK)

and

"The HAL_I2S_RxCpltCallback doesn't do anything right now and the I2S2 is not started with the DMA."

Do you mistype, and should be I2S1 is not started?

Anyway, I never tested I2S + dma transferring only one word, but I envision that uCPU would have hard time to figure out when to fire TransferComplete & TransferHalfComplete interrupts, since half of 1 is 0 in integers.

Try to increase size of data to be transferred.

What is the size of output_buffer?

What memory it's located?

Has DMA access to this memory?

[Gkatsos]

Sorry wrote the wrong function, I2S2 is not started, the code running is initially is:

void Start_I2S1_Receive(void)
{
	if (HAL_I2S_Receive_DMA(&hi2s1, (uint16_t*)&input_buffer, 1) != HAL_OK) 
	{
		Error_Handler();
	}
}

[Gkatsos]

A follow up.

I have also tried setting up SAI, here all the clocks are correct, but I again experience stutter.

[Gkatsos]

I have tried with a lot of different buffer sizes.