VDD11 pin connected to ground

[Theneka]

Hello, 

I designed a PCB using the STM32U575ZIT6Q. I do not use SMPS on this board. I am using a external 3.3V supply.

When designing, I connected the VDD11 pins to ground as shown here.

But now when I am trying to debug the PCB, the microcontroller doesn't seem to respond to my attempts to program it. I was looking at my schematic and spotted this. When searching more online about VDD11 i found this: 

How necessary is it to connect this pin through these capacitors? I didn't see this and I am wondering if this is the problem with my PCB design, or if I should look for it somewhere else.

What can I do to fix this if it is an issue?

Thanks for the help.

[AScha.3]

Hi,

>What can I do to fix this if it is an issue?

Connect 2u2 cap Vdd11 to GND.

>How necessary is it to connect this pin through these capacitors?

Depends, whether you want the cpu core supply with some (1v1 or so) voltage and have the needed bulk capacitance there, or not.

Still the board can be used to show, that a cpu without power is not working.

[Theneka]

Hi,

what exactly do you mean with this?
>Depends, whether you want the cpu core supply with some (1v1 or so) voltage and have the needed bulk capacitance there, or not.

Is there any way to test if the µC is working or not without being able to program it? It could be that this isn't my issue.

I am supplying the STM with 3.3V and using it's GPIO and i am also using SPI.

[AScha.3]

Hi,

sorry, if not clear to you:  the cpu needs some power, supply; this is buffered at V11 pins.

Short them to GND and nothing can work.

So , if

No power on core = no working cpu ever.

->

>What can I do to fix this if it is an issue?

Connect (2x )   2u2 cap Vdd11 to GND.