Debug losing connection with Stm32WB55 target

GYV · ‎2026-02-03

Code is written using stm32CubeMX. Connecting with stmlink V3 Minie.
Executing step by step, it appears that debug fails (lose connection) when executing debug_init. In fact debug_init creates the problem when programming pa13.
When removing the initialization of PA13 and PA14 in debug init, things seems to work but I have no idea of potential side effect.
An recommendation?

TDK · ‎2026-02-03

Please include the IOC that generates the problematic code.

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Andrew Neil · ‎2026-02-03

Welcome to the forum.

Please see How to write your question to maximize your chances to find a solution for best results.

In particular, please give details of your setup.

@GYV wrote:
debug fails (lose connection) when executing debug_init. In fact debug_init creates the problem when programming pa13.

Please show that code. See: How to insert source code

PA13 & PA14 carry the SWD signals (ie, the signals the debugger uses to communicate) - so messing with them will break the debugger connection!

https://www.st.com/resource/en/datasheet/stm32wb55rg.pdf#page=65

via: https://www.st.com/en/microcontrollers-microprocessors/stm32wb55rg.html#documentation

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.