STM32F205 bootloadet USB DFU mode

[alexandre.bulfay]

Hy,

I'm trying to run the DFU mode with a STM32F205. When I put boot0 to VCC and I do a reset, the DFU USB was not detected by my computer. Can someone help me ?

I tried before that on the nucleo card F207ZG and this work corectly.

[Tesla DeLorean]

Check levels on USB pins, and make sure D+/D- not swapped.

Does USB work from your own code loads?

Do you have an 8 MHz crystal or clock source?

[alexandre.bulfay]

USB in my own code works correctly. And I have a 6MHz crystal.

[alexandre.bulfay]

Someone know how the cable USB is detected ?

[Tesla DeLorean]

I believe it looks for a bias on the pins.

Is 6 MHz a supported frequency per AN2606​? Does it start quick enough?

[alexandre.bulfay]

AN2606 say "An external clock multiple of 1MHz (between 4 and 26MHz) is required for CAN and DFU bootloader execution after the selection phase." So normaly 6MHz is supported.