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Enumeration fails when Host boot up

Question asked by K.G..Pramod on Apr 4, 2017

Hi all, 

I am using CubeMx generated code for USB Host- CDC communication. With this code Enumeration fails under two scenarios

1) Host attached to a CDC device(CDC device not powered externally) then Power on Host.

2) Host attached to a CDC device(CDC device is powered from external source) then power on Host.

My observation is that Enumeration fails always when Host power up if a device is already attached into it. In all the other scenarios (Connecting Device when host is powered On, multiple plugging and unplugging etc) it works fine.


Both Host and Device uses STM32F479 MCU.

If anyone have solution or faced this issue, please share your thoughts



usb enumeration

stm32f usb

Best Regards,