USB Full Speed MSC using uSD (SMMC2) and FatFs took so long to enumerate

[Jtron.11]

I am using STM32F722ZE MCU. I am successfully implemented micro SD FATFS USB Full Speed MSC.

The problem is every time I plug the board to PC, it took so long, up to 40 seconds, for the USB enumeration to be completed.

Can anyone help me to point out for me there is something that I missed or any way to speed it up?

I used the same board and create USB Full Speed MSC using MCU's RAM and the USB enumeration happened as soon as I plugged the USB in the PC host.

[Walid ZRELLI]

Hello @Jtron.1​ ,

MSC_MEDIA_PACKET is used to adjust the MSC class Data buffer this is not coupled with uSD sector size at all.

If you use dynamic allocation, you have to adjust the heap size.

Since the RAM size is too small, it is normal to have zero latency! Even in FS mode.

BeST Regards,

Walid

[Jtron.11]

Hello @Walid ZRELLI​ ,

Thank you for additional info. What would I should do next for trouble shoot this issue? You now have exactly source code, could you please, if it is possible, using my source code and run on the eval and external uS module.

This is the external uSD module that I am using https://www.adafruit.com/product/4682

Thank you for your helps.

[Jtron.11]

Hello@Walid

May I ask if you have any chance to run my code to see the problem?