I have bought a batch of STM32F750N8 MCU's and have found that the following pins do not work. PB14, PB15, and PA12/PA11.

[PMold.1]

I have tried turning these pins to GPIO's and tried toggling them, however, they seem to just be floating. I can confirm that these pins have been soldered on properly, since I have checked them using an X-RAY inspection system. I can also confirm that all the other pins around work too. Could these chips be faulty or is there any other reason as to why these pins would not work?

[TDK]

It's most likely a hardware issue. Nothing particularly special about those pins, certainly nothing unique which would explain all of them not working. Could be a soldering issue or a board manufacturing issue. Can you test on multiple boards?

If you set the pins as output and the bits in the GPIO->IDR register match up with the bits in the GPIO->ODR register for those pins when toggled, they are probably just not connected.

[waclawek.jan]

> I have tried turning these pins to GPIO's

How, exactly?

These pins are OTG_FS/HS DP/DM. and are supplied from the VDDUSB pin.

JW

[Tesla DeLorean]

Any details about package, production date, or stepping?

"VDDUSB USB supply voltage (supply voltage for PA11,PA12, PB14 and PB15 pins) "

[PMold.1]

Yes, looks like my VDDUSB pin is grounded. Thank you!