STM32F7508-DK: SD Card Interface Working in 1-Bit Mode, Fails in 4-Bit Mode

[ajith1]

Hi STM32 Team,

I am working with the STM32F7508-DK development board and interfacing it with an SD card using the SDMMC peripheral. The 1-bit data transfer mode works flawlessly, but when switching to 4-bit mode, the interface fails to operate as expected. 

Please guide me to resolve this issue. 

Thanks and Regards,

A. Ajith Kumar

[SofLit · Accepted solution]

Hello @ajith1 ,

Look at this thread:

https://community.st.com/t5/stm32cubemx-mcus/sdio-interface-not-working-in-4bits-with-stm32f4-firmware/td-p/591776

1. Step 1 - hsd.Init.BusWide set to SDIO_BUS_WIDE_1B just for initialization.
2. Step 2 - Call HAL_SD_Init(&hsd)
3. Step 3 - Call HAL_SD_ConfigWideBusOperation(&hsd, SDIO_BUS_WIDE_4B)

static void MX_SDIO_SD_Init(void)
{

  /* USER CODE BEGIN SDIO_Init 0 */

  /* USER CODE END SDIO_Init 0 */

  /* USER CODE BEGIN SDIO_Init 1 */

  /* USER CODE END SDIO_Init 1 */
  hsd.Instance = SDIO;
  hsd.Init.ClockEdge = SDIO_CLOCK_EDGE_RISING;
  hsd.Init.ClockBypass = SDIO_CLOCK_BYPASS_DISABLE;
  hsd.Init.ClockPowerSave = SDIO_CLOCK_POWER_SAVE_DISABLE;
  hsd.Init.BusWide = SDIO_BUS_WIDE_1B;
  hsd.Init.HardwareFlowControl = SDIO_HARDWARE_FLOW_CONTROL_DISABLE;
  hsd.Init.ClockDiv = 0;
  if (HAL_SD_Init(&hsd) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_SD_ConfigWideBusOperation(&hsd, SDIO_BUS_WIDE_4B) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN SDIO_Init 2 */

  /* USER CODE END SDIO_Init 2 */

}

 Hope it helps.