STM32H573: ETH SWRESET fails, ETH_DMAMR_SWR stays set, timeout

[Lionheart1810]

I want to initialize the STM32H573 ETH module using the STM32CubeMX code generator (see ioc file attached). It should run in MII mode using an external transceiver.

I kept the configuration unchanged, however it always jumps to ErrorHandler, because HAL_ETH_Init returns HAL_ERROR on timeout of ETH_DMAMR_SWR at the following routine:

  SET_BIT(heth->Instance->DMAMR, ETH_DMAMR_SWR);

  /* Get tick */
  tickstart = HAL_GetTick();

  /* Wait for software reset */
  while (READ_BIT(heth->Instance->DMAMR, ETH_DMAMR_SWR) > 0U)
  {
    if (((HAL_GetTick() - tickstart) > ETH_SWRESET_TIMEOUT))
    {
      /* Set Error Code */
      heth->ErrorCode = HAL_ETH_ERROR_TIMEOUT;
      /* Set State as Error */
      heth->gState = HAL_ETH_STATE_ERROR;
      /* Return Error */
      return HAL_ERROR;
    }
  }

From what I've read on this forum, the ETH somehow needs an external clock input from the transceiver. However, ETH_REF_CLK is only defined in RMII mode, but I want MII mode with RX and TX clocks. Does it still need permanently running clock? ETH_RX_CLK is currently served from the transceiver with 2.5 MHz (in 10 Mbps mode), the ETH module itself is clocked 100 MHz from PLL1Q:

I even tried rising the timeout threshold, but even 50 s is failing. Any ideas on how to get the initialization through?

[alister]

ETH_REF_CLK is for RMII. ETH_RX_CLK and ETH_TX_CLK are for MII.

I observed HAL_ETH_Init failing similarly for the STM32H7S78-DK last year and posted that and a fix at https://community.st.com/t5/stm32cubemx-mcus/bugs-caveats-misc-fixes-stm32h7s-cube/td-p/710992. For clarity, the peripheral clock's fix in HAL_ETH_MspInit was:

 PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_ETH1REF;
 PeriphClkInit.Eth1RefClockSelection = RCC_ETH1REFCLKSOURCE_PHY;

[Lionheart1810]

This section does not exist in the autogenerated HAL_ETH_MspInit:

Spoiler

void HAL_ETH_MspInit(ETH_HandleTypeDef* heth)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(heth->Instance==ETH)
  {
  /* USER CODE BEGIN ETH_MspInit 0 */

  /* USER CODE END ETH_MspInit 0 */
    /* Peripheral clock enable */
    __HAL_RCC_ETH_CLK_ENABLE();
    __HAL_RCC_ETHTX_CLK_ENABLE();
    __HAL_RCC_ETHRX_CLK_ENABLE();

    __HAL_RCC_GPIOB_CLK_ENABLE();
    __HAL_RCC_GPIOG_CLK_ENABLE();
    __HAL_RCC_GPIOC_CLK_ENABLE();
    __HAL_RCC_GPIOH_CLK_ENABLE();
    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**ETH GPIO Configuration
    PB8     ------> ETH_TXD3
    PG14     ------> ETH_TXD1
    PG13     ------> ETH_TXD0
    PG11     ------> ETH_TX_EN
    PC1     ------> ETH_MDC
    PC2     ------> ETH_TXD2
    PC3     ------> ETH_TX_CLK
    PH6     ------> ETH_RXD2
    PA1     ------> ETH_RX_CLK
    PA0     ------> ETH_CRS
    PC4     ------> ETH_RXD0
    PH7     ------> ETH_RXD3
    PA2     ------> ETH_MDIO
    PC5     ------> ETH_RXD1
    PA3     ------> ETH_COL
    PA7     ------> ETH_RX_DV
    */

    GPIO_InitStruct.Pin = GPIO_PIN_8;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF11_ETH;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

    GPIO_InitStruct.Pin = GPIO_PIN_14|GPIO_PIN_13|GPIO_PIN_11;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF11_ETH;
    HAL_GPIO_Init(GPIOG, &GPIO_InitStruct);

    GPIO_InitStruct.Pin = GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3|GPIO_PIN_4
                          |GPIO_PIN_5;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF11_ETH;
    HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

    GPIO_InitStruct.Pin = GPIO_PIN_6|GPIO_PIN_7;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF11_ETH;
    HAL_GPIO_Init(GPIOH, &GPIO_InitStruct);

    GPIO_InitStruct.Pin = GPIO_PIN_1|GPIO_PIN_0|GPIO_PIN_2|GPIO_PIN_3
                          |GPIO_PIN_7;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF11_ETH;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /* USER CODE BEGIN ETH_MspInit 1 */

  /* USER CODE END ETH_MspInit 1 */

  }

}

Also, there is no RCC_PERIPHCLK_ETH... (as it is most likely directly clocked from PLL1Q).

Anything I am missing?

[alister]

My bad, my clock fix applies the STM32H7S/R, not the STM32H7!

I've not used newer than Cube v5.5 with an STM32H7... Check your Cube generated code for the following macros. The __HAL_RCC_GPIOx macros are only necessary for the GPIO ports that have pins connected/used.

    __HAL_RCC_ETH1MAC_CLK_ENABLE();
    __HAL_RCC_ETH1TX_CLK_ENABLE();
    __HAL_RCC_ETH1RX_CLK_ENABLE();
  
    __HAL_RCC_GPIOC_CLK_ENABLE();
    __HAL_RCC_GPIOA_CLK_ENABLE();
    __HAL_RCC_GPIOB_CLK_ENABLE();

Check other resources:

• Example code at https://www.st.com/en/embedded-software/stm32cubeh7.html.
• Knowledge base at https://community.st.com/t5/stm32-mcus/how-to-create-a-project-for-stm32h7-with-ethernet-and-lwip-stack/ta-p/49308. There's a diagram of the required clock config there.
• Community search, as STM32H7 ETH is discussed often.

[alister]

The code you mention isn't included in your Cube-generated HAL_ETH_MspInit looks very familiar. You need all of that.

[alister]

Please post whether it's an ST dev board and which one, or a custom board, your Cube version, and if it's an ST dev board, whether you loaded the board's default config in Cube.

@STea, could you or a colleague assist Lionheart1810 please?

[Lionheart1810]

I am using STM32H573, not STM32H7 series.

STM32CubeMX version: 6.13.0
Firmware package version: STM32Cube FW_H5 V1.4.0

It is a custom board. I use DP83826 as Ethernet transceiver and 25 MHz oscillator. However, afaik it should be independent of the transceiver in MII mode for the reset.

I tried figuring it out and adding the missing code myself, but there are no such RCC_PERIPHCLK_ETH... macros in the entire HAL. I also just tried to initialize a blank project with just ETH enabled without success.

[waclawek.jan]

PHY is the clock source for both Rx and Tx in MII mode.

So, you need the TX_CLK and RX_CLK outputs from PHY to be connected to ETH_TX_CLK and ETH_RX_CLK pins (marked in DS as ETH_MII_TX_CLK=PC3 and ETH_MII_RX_CLK=PA1) of the 'H5 respectively. These pins have to be set to AF in GPIOx_MODER and to the proper AF number (11) in GPIOx_AFR[]. Besides, RCC_AHB1ENR.ETHEN, .ETHTXEN, .ETHRXEN must be set (all 3 bits).

Read the RCC and ETH chapters in Reference Manual.

If CubeMX/Cube/HAL does not work for you, well, just don't use it, and program through registers directly.

PHY of course must be strapped (or configured through SMI) to MII mode.

JW

[Lionheart1810 · Accepted solution]

Figured out the error. I was missing the propagation of the reset signal to the external PHY for bootstrap configuration. Just added it to the HAL_ETH_MspInit.