USB dead without obvious reason

[Stanislav Husár]

Hello,

I have problems with custom designed board. After soldering everything(w/o IC1,IC3) I flashed my firmware. USB device completely unrecognized.

I have soldered 1k5 resistor on 3V3 and D+. After connecting to computer I was able to see serial output on terminal program.

Then I have shorted pins 1-6 on IC1 to connect positive analog reference. After connecting, USB peripheral apparently died.

No matter what I flash, I get device descriptor request failed. I have also tried USB VCP project template, same result.

Any idea what did I do wrong? Is there any chance to get it working, besides soldering a new mcu?

Thanks in advance,

Stanislav

[Stanislav Husár]

Okay, I got tricked by RMW again. SW_HSE | SW_PLL is not a valid clock.

But if I comment lines 8-9, nothing changes. Funny thing is, debugger says that RCC->CFGR is 0x001D000A. That is SW_PLL and SWS_PLL.