STM32F769 VDDUSB

[UB40]

Hello,
I'm using in my projects with ports PA10,PA11 (for Logs - uart), and PB14 and PB15 as normal GPIO.
They didn't works.

After long troubleshooting.... I found out that is because these ports are supply separately by the VDDUSB pin which was disconnected.

I couldn't find the reason in the datasheet, I'll be happy to understand the construction and the reason. 

[AScha.3 · Accepted solution]

Hi,

reason...ask chip designer, why separate VddUSB ...maybe, to be more flexible, if chip runs on 1,8V, the USB related pins still have to work on 3v3 ; so can supply separate, if needed;

and see ds :  General operating conditions

[UB40]

thank you