STM32H750B-dk: access eMMC through USB OTG

[Prajyot1]

Split from this thread as it has been solved, and this is a new question:

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How to access eMMC through OTG on STM32H750B-DK kit.?

[Prajyot1]

How to configure eMMC to access through OTG.?

[FBL]

Hi @Prajyot1 

You can start with the example to read and write to eMMC card as a first step. Then, you can refer to the application on how to interface to a PC host through USB MSC. The application itself uses SD card as storage media so in your case you need to use eMMC instead .

[Prajyot1]

Hello @FBL 
i was able to read write to eMMC card with the help of `~\STM32Cube_FW_H7_V1.12.1\Projects\STM32H745I-DISCO\Applications\FatFs\FatFs_Shared_Device` and `~\STM32Cube_FW_H7_V1.12.1\Drivers\BSP\STM32H750B-DK`. the next i want to use eMMC as Storage Media.

[FBL]

Hi @Prajyot1 

JP8 is configured on ST Link only. I have 2 cables used one for ST Link interface (+power) over CN14 and the other for USB communications over 'CN13'. 

[Prajyot1]

yes i have tried that too just now .. but still same issue.. if it either configuration issue or coding issue?

[Prajyot1]

UPDATE:
the PC detects eMMC sometimes and sometimes it doesn't when i plug it into PC. Also i am not able to format this disk too. it gets disconnected after sometime.

 

[FBL]

Hi @Prajyot1 

indeed, SDMMC peripheral clock and prescaler affects the SDMMC clock speed. Slower clock means slower initialization and data transfer. If you have debug prints, check the time spent in eMMC initialization and FatFS mount. Try lowering the prescaler value to speed up data transfer.

TouchGFX relies on LCD-TFT Controller Clock. 

• Verify that the LTDC clock source and prescaler are set correctly according to your display specs.
• Make sure the framebuffer is properly allocated and accessible.
• Ensure DMA is enabled and cache coherency is maintained.