My own L452 board stops working when I press NRESET, problem with debbuging but not flshing.

[HHako.1]

Hello to everyone,

I have crereated my own STM32L452 board with battery power supply.

It dosent run as expected. Sometimes I need to discharge caps and sometimes this is not helping. When it works and I connect nreset to groung and release it stops working, I need to powewr off and repeat mentioned process. I can flashe the code but have a problem with online debbuging (ususaly I louse connection). Somtimes it stops working when the process reaches to delays. When it works in DP port voltaghe level is low and when it not working this pin is high. 

I have disconnected NRESET pin from board and this is not helping.

I have attaced the footprint of my board (mcu part).

What to do ?

[Tesla DeLorean]

BOOT0 pulled low?

Hanging up related RTC reset?

[HHako.1]

No I it is free, not connected like previouse version, but previouse version works great.

[TDK · Accepted solution]

> No I it is free, not connected like previouse version, but previouse version works great.

If BOOT0 is floating, that would explain it not running user code.

Tie BOOT0 to ground, or set nSWBOOT0=0 and nBOOT0=1 in option bytes (OB tab in STM32CubeProgrammer).

[HHako.1]

Thank you, works.