Nucleo-L5 SDMMC peripheral unable to run with HAL, SDMMC, FATFS

[JTedot]

Goal: Create a filesystem on SD-card with the SDMMC-interface.

The guide here (which should not differ for this MCU) features DMA-settings, which the L5 does not have. It seems as if a bunch of functionality is missing. Why can't I enable DMA for the SDMMC-interface?

No DMA-tab visible 

Brute-forcing it returns `FS_NOT_READY` and measuring the clock-pin (which should carry a signal for **any** data-transfer) stays idle. I'm assuming that a function is calling a non-implemented weak function which doesn't actually do anything. Is there any way to run the SDMMC-peripheral manually on the L5?

[Amel NASRI]

Hi @Sara BEN HADJ YAHYA​ ,

Do you confirm if the behavior described by @JTedot​ is a known limitation?

-Amel

[Sara BEN HADJ YAHYA]

Hello @JTedot​ ,

Thanks for your feedback,

Actually this is not an issue, for STM32L5 and STM32H7 devices, SDMMC peripheral include an internal DMA (IDMA).

For more details please check the Reference manual or this presentation.

I hope this helps :smiling_face_with_smiling_eyes:

If your issue is solved, please close this post by clicking the "Select as Best" button. This will help other members of the community find this response more quickly :)

Sara.

[JTedot]

The presentation sadly does not state how the HAL is connected to the peripheral and no examples are available. As I stated before, no signal line is being driven, which means that the hardware is not accessed. Can you provide an example to the SDMMC usage of the L5 using the HAL?

[Sara BEN HADJ YAHYA]

Hello @JTedot​ ,

There are some FatFS with SDMMC peripheral examples for L5. They are placed under C:\Users\benhadjs\STM32Cube\Repository\STM32Cube_FW_L5_V1.4.0\Projects\STM32L552E-EV\Applications\FatFs

I hope this helps :smiling_face_with_smiling_eyes:

Sara.