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STM32U5A9J-DK1 USB Device as mass storage standalone via sdmm1 emmc

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tod
Associate II

‎2025-09-12 7:36 PM - last edited on ‎2025-09-16 5:54 AM by

I want to use the EMMC as USB storage space, but I encountered another issue: I am trying to access the EMMC via SDMM1, and after implementing the MSC-related functions (read, write, USBD_STORAGE_GetMediaLastLba, USBD_STORAGE_GetMediaBlocklength) in ux_device_msc.c, the formatting operation on the PC side fails. The error message says: "Please insert a disk into the removable disk."
I have already verified that after initializing SDMM1, the EMMC can be accessed and read/write operations are successful.

What could be the reason for this issue?

The attached file is my project.

tod_0-1757730569995.png

ux_device_msc.c：

tod_2-1757730678625.png

tod_4-1757730856986.png

 

tod_3-1757730698364.png

 

 

 

Labels:
MSC-FIN.7z
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10 REPLIES 10
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tod
Associate II
In response to FBL

‎2025-09-23 11:54 PM

Hi @FBL 

Thank you so much for your help! With your assistance, I have successfully formatted it as well.
However, I noticed that the file read/write transfer speed is very slow (1-2 MB/s). Is it possible to improve the read/write speed by adding ThreadX or using DMA?

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