STM32G0B0 ROM Bootloader USB DFU

[SageTech]

Hi,

I have been able to use the option bytes to configure the Nucleo-G0B1RE to jump straight into the ROM bootloader on powerup and I can see the DFU on Cube Programmer, however on our target board with a G0B0 using the same user option bytes settings I have not been able to get it to come up on the computer. I have been able to use a simple virtual com port project to verify that USB is working on the target board. What could be causing the bootloader DFU to fail to enumerate, or cause the bootloader to not run in the first place?

[SageTech]

As it turns out the G0B0 requires an external oscillator for the bootloader to use USB. The G0B1 has a 48MHz internal oscillator that it uses in the bootloader for USB and does not require an external oscillator. Long term we'll have to add an oscillator to our board to use the G0B0, and in the short term we're planning to swap to the G0B1 on our existing boards.