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SAlug.1
Associate II
March 30, 2022
Question

USB interrupt issue after NVIC System Reset on STM32F411CCU6TR

  • March 30, 2022
  • 2 replies
  • 2148 views

A PC app sends a reset command via USB. In the main app I use HAL_NVIC_SystemReset() to reset the board. If I use HAL_NVIC_SystemReset, windows loses USB com port and does not re-enumerate port unless I plug out and plug in USB cable.

The PC app talks to USB virtual com port.

Schematics

0693W00000LwFudQAF.png0693W00000LwFvvQAF.png 

Please support to fix this.

This topic has been closed for replies.

2 replies

waclawek.jan
Super User
March 30, 2022

Remove R3.

JW

SAlug.1
SAlug.1Author
Associate II
March 30, 2022

We have Remove R3 register and the USB enumeration is happening after issue NVIC_SystemReset(). Thanks for the help

gbm
Lead III
March 30, 2022

Also make sure that USB peripheral is not activated immediately after reset, Windows correctly re-enumerates USB device if it is disconected for at least some minimum time. Try to delay 20..100ms before enabling USB. 20ms delay works for me.

My STM32 stuff on github - compact USB device stack and more: https://github.com/gbm-ii/gbmUSBdevice