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why the stm32usb_cdc entering into DFU mode when I connected with pc

RKUMA.2
Associate II

Hello,

I am working on the stm32f070c6 ,I wrote the code for usb_cdc , when I was connected with pc it was either showing as DFU mode or STM32 boot loader, it is not detected as COM port . why it is entering into DFU mode how to overcome and how it will detect as COM port , the code and everything is okay(no errors )

5 REPLIES 5

BOOT0 is HIGH, or the part is blank? ​

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Thanks for your reply @Community member​ , when I uploading the program boot0 pin connected to high, if I disconnect the boot0 pin from vcc , it shows as usb device descriptor request failed, if i make boot0 pin to high , it is showing as in device manager window either DFU MODE/ stm32 bootloader. it is not detected as COM port

So a code/implementation issue on the CDC​

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RKUMA.2
Associate II

@Community member​  The code is correct because I took the reference from the st website

TDK
Guru

When BOOT0 is high, it enters the system bootloader (DFU mode).

As for why it's not working in CDC mode with your code, probably a firmware issue.

> the code and everything is okay(no errors )

You mean no errors when compiling? Hardly means the code is okay.

At least since it enters DFU mode, you can rule out any hardware issues related to the USB lines.

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