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Associate III
March 31, 2026
Solved

STM32F407 Breakpoint crossed-out

  • March 31, 2026
  • 5 replies
  • 336 views

When i try to add breakpoint, there is a cross sign on breakpoint symbol. So even if the code works, breakpoint never works.

I try to add __asm("BKPT 0"); but it also did not work.

 

I am not sure what is the problem.

My CubeID version is: 

Version: 2.1.1

Build: 28236_20260312_0043 (UTC)

Best answer by Andrew Neil

CubeIDE is built on Eclipse, so it's often useful to search the internet using "Eclipse" rather than "CubeIDE" as a keyword.

eg, googling "eclipse crossed-out breakpoint" found this - does that help?

 

(other internet search engines are available)

5 replies

Andrew Neil
Super User
March 31, 2026

Are you trying to place a breakpoint where there is no actual code?

Please show a screenshot of what you're seeing.

 

Please give details of your board, and what debug probe you're using - see: How to write your question to maximize your chances to find a solution

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.
Associate III
March 31, 2026

break point.jpg

Andrew Neil
Super User
March 31, 2026

You didn't answer the other question:

Please give details of your board, and what debug probe you're using

 

Are you able to single-step that code?

Can you place breakpoints elsewhere?

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.
Associate III
March 31, 2026

My board is STM32F407 discovery. I connect my board with USB-cable. For UART, i use TTL converter. I did not do single-step. When UART gets data (LED_ON) command from hercules, with my setup program must stop. But LED becomes on but program did not stop at the line which is on screenshot. I did not use specific probe or any kind of tool. My setup is basic.

Andrew Neil
Super User
March 31, 2026

@tensaisakuragi06 wrote:

 I did not do single-step..


Please try it - does it work ?

Also please try setting breakpoints elsewhere - do they work ?

 


@tensaisakuragi06 wrote:

 I did not use specific probe or any kind of tool. 


The STM32F407 discovery board has a built-in ST-Link

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.
Associate III
March 31, 2026

Whenever i add breakpoint it displays a cross symbol on it. Videos on internet, other ppl breakpoints doesnt not have a cross symbol on it. I try step-by-step, putting different lines of codes, inside the uart interrupt, outside the interrupt, inside the main etc. Breakpoint is not active. I made search about it but can not solve it yet.

Andrew Neil
Andrew NeilBest answer
Super User
March 31, 2026

CubeIDE is built on Eclipse, so it's often useful to search the internet using "Eclipse" rather than "CubeIDE" as a keyword.

eg, googling "eclipse crossed-out breakpoint" found this - does that help?

 

(other internet search engines are available)

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.
Associate III
March 31, 2026

Thank you. I try to figure out for 1 day. On ..flow forum, they mention  a settting which is Run> Skip all Breakpoint. In my setting this is selected. But i am sure i did not select it.