Issue with SDIO Initialization Causing MCU Communication Failure on Custom STM32H747 Board

[Samudra]

Dear sir,

In our custom board, we are using the STM32H747XIH6 microcontroller with Wi-Fi functionality. The Wi-Fi module part number is LBEE5KL1DX-883, and it is connected via the SDIO interface.
We have properly configured the I/O pins in STM32CubeMX and generated the code. However, once the SDIO initialization is executed, we are unable to communicate with the MCU.
Without SDIO initialization, the board works fine.
Could you please help us identify the issue?

Best regards,

Samudralnakaiah.

[Imen.D]

Hello @Samudra ,

Check the SDIO configuration in STM32CubeMX, the pin assignments and alternate function settings (make sure that no conflict with other pins). Also, check the clock speed, data width as required by the SDIO specification in the product Datasheet (SDIO pins - pull-up/down resistors).

I advise you testing with an oscilloscope or logic analyzer to check SDIO signals (CLK, CMD, DATA lines).