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USB Host STM32 Fxxx and Lxxx do not work with LS hid via external hub

VAlec.1
Associate II

I know that there are problems with the F and L series mcu running through an external hub and ls hid device.

See https://www.segger.com/downloads/emusb-host/UM10001.

paragraph 19.3.2.2 Restriction

I don't know why it's not in the errdata.

For this reason, there is probably no hub class for such a long time. Although it is quite simple to implement.

I've seen it on my own experience, when working through an external hub errors occur when passing the usb transaction

with SYNC PRE. MP series, where this problem does not exist, is very expensive and redundant.

Is there a software solution to this problem?

What internal causes resets the usb port?

Which mcu can you recommend to use for working through an external hub fs and ls hid device?

2 REPLIES 2
NotSoMega
Associate III

Hello, I had the same issues as you described. In this post I described my problem:

https://community.st.com/s/question/0D50X0000BHydBQSQZ/stm32f429-discovery-as-usb-host-problems-enumerating-lowspeed-device-over-fullspeed-hub

Here I am currently working on a solution by using High Speed and the Split Protocol instead of preamble PID:

https://community.st.com/s/question/0D50X0000CCrtBiSQJ/high-speed-usb-split-transaction-stm32f723

ST has not been very helpful and it seems they would rather ignore this problem than working on a solution. I was told this problem would be included in an errata at the end of last year. I haven't seen it, yet.

VAlec.1
Associate II

Thank you for the answer,

I see you've done a lot of work.

Unfortunately, these issues have not been resolved for more than five years.

I'm starting to learn nxp, maybe it'll work better.