STM32U5A9J-DK1 UsbX Device MSC standalone + SDMMC DMA transfer speed

[tod]

Hi all,

I want to use the EMMC as USB storage space.After connecting to the computer and successfully formatting, I found that the file transfer speed is very slow (write speed is 1-2 Mb/s, read speed is 2-6 Mb/s).
After enabling DMA, the speed still hasn't improved.

And I referred to an example(https://github.com/STMicroelectronics/x-cube-azrtos-h7/blob/main/Projects/STM32H735G-DK/Applications/USBX/Ux_Device_MSC) and switched the read/write interface to DMA(BSP_MMC_WriteBlocks_DMA,BSP_MMC_ReadBlocks_DMA), but the enumeration failed. Is this due to differences in the chip series or incorrect configuration?

Aside from this, are there any other methods to improve the speed?

The attached file is my project.

[tod]

Hi @FBL 

Could you provide some advice? I would really appreciate it!

[FBL]

Hi @tod 

This Internal DMA you mention is specific to USB controller. However, BSP_MMC_ReadBlocks_DMA/BSP_MMC_WriteBlocks_DMA are specific to SDMMC interface.  You can follow this CKB-STM32-MSC-UX-Standalone-U5 and enable DMA mode here.

[tod]

Hi @FBL 

Thank you very much for your suggestions!

I will refer to them and provide feedback on the results.