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A
ayaaaa
Associate II
April 28, 2026
Question

STM32N657 XIP + STM32CubeAI Studio – aiRun() stuck in LL_ATON_RT_WFE loop

  • April 28, 2026
  • 7 replies
  • 265 views

 

Hello,

I’m working on a project generated by STM32Cube AI Studio targeting the NUCLEO-N657X0-Q, using an XIP configuration with external XSPI flash ( It was said in another post that the generated projects from STM cube AI Studio follow XIP configuration).

Setup

  • Board: STM32N657X0-Q
  • Toolchain: STM32CubeIDE(2.1.1) + STM32CubeProgrammer(2.22.0)
  • Project generated with STM32Cube AI Studio
  • Execution mode: XIP (application in external flash)
  • Runtime: Bare metal (LL_ATON_OSAL_BARE_METAL)

Memory mapping

Model location (from generated network.c):

.addr_base = (unsigned char *)(0x71000000UL)

Programming steps

I programmed manually using STM32CubeProgrammer:

  • second_Appli.elf 
  • network_atonbuf.xSPI2.bin → placed at 0x71000000

Debug configuration (FSBL project)

I start debugging from the FSBL project.
In Debug Configuration → Startup → Load Image and Symbols, I configured:

  • second_Appli.elf
    • Download = OFF (already flashed manually)
    • Load symbols = ON

So FSBL is loaded/debugged, while App and model are already present in flash.

Additionally, I also tried adding the runtime GCC libraries to the FSBL debug configuration, but this did not change the behavior

 What works

  • FSBL runs correctly from RAM (0x3418xxxx)
  • XSPI initialization seems correct
  • Jump to application works

  • Application reaches:

     
    STM32CubeAI_Studio_AI_Init();
    STM32CubeAI_Studio_AI_Process();
     

  • Execution enters:

     
    aiRun();
     

 Problem

Execution gets stuck in:

 

 
do {
ll_aton_rt_ret = LL_ATON_RT_RunEpochBlock(&NN_Instance_network);

if (ll_aton_rt_ret == LL_ATON_RT_WFE)
LL_ATON_OSAL_WFE();

} while (ll_aton_rt_ret != LL_ATON_RT_DONE);
 

 

Observed behavior:

  • ll_aton_rt_ret remains LL_ATON_RT_WFE
  • Loop never exits

Question

  • is this the right debug configuration for projects generated by STM Cube AI Studio ?
  • if so ,is there additional steps before debugging so that the inference ?

Thanks for your assistance 

7 replies

A
ayaaaaAuthor
Associate II
April 28, 2026

 

 Additional debug attempts (LED + UART)

 LED test

To verify that the application is actually running, I added a simple GPIO test:

  • Configured a GPIO pin as output in MX_GPIO_Init()
  • Set the pin high before and after aiRun()

Result

  • The code does reach the LED control function
  • However, the LED does not visibly toggle .

UART / printf test

I also tried UART debugging. USART1 is initialized and I have used USART1 successfully on the same board in other projects. However, in this Cube AI Studio project, printf does not output anything. I noticed that _write() is already defined in aiTestUtility.c, so I did not add a duplicate _write() in main.c.

 Interpretation

  • The application does execute (Confirmed by code stepping)
  • But : aiRun() never completes (still stuck in LL_ATON_RT_WFE)
  • Could not debug with printf /leds as they dont output anything despite not having any building errors and the code stepping in their functions .

Can you please provide and explanation/tutorial that would be very helpful 

A
ayaaaaAuthor
Associate II
April 29, 2026

Update : 

I now understand that not being able to use the virtual com port or leds to debug was because they were not configured in the generated Cube mx project , but i still didnt find a solution to the inference stuck in the aiRun() Loop

A
ayaaaaAuthor
Associate II
April 30, 2026

i attach here my full project on zip format 

can you please look into it 

hamitiya
hamitiya
ST Employee
May 4, 2026

Hello @ayaaaa 

On my side, your project is not stuck in the while loop:

hamitiya_0-1777895606136.png

I will share with you a NUCLEO-N657X0-Q project with outputs in UART, if it works on your side, I will try to help you to modify the model integrated in it.

 

Best regards,

Yanis

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A
ayaaaaAuthor
Associate II
May 5, 2026

Thanks for your reply ! 

Okay i see , i must be doing something wrong then in the debugging phase , can share with me please how you debugged (app/fsbl) with options and also the positions of boot 0 and boot1. Thanks 

hamitiya
hamitiya
ST Employee
May 5, 2026

Hello,

Yes, startup is quite tricky. 

Either you start using this tutorial: How to debug STM32N6 using STM32CubeIDE - STMicroelectronics Community

Or, you can avoid signing procedure by:

- Flash Appli.elf with STM32CubeProg

- Power cycle your board

- Start your debug session with FSBL, and "Download" only the FSBL .elf file. 

 

Best regards,

Yanis

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A
ayaaaaAuthor
Associate II
May 5, 2026

i did actually end up following the tutorial ( which i did in my intiial project too ) 

this is the configuration : 

ayaaaa_0-1777963252477.png

i ended up with the same error on the fsbl debug too !

ayaaaa_1-1777963285987.png

I figured it might be a board problem , but its not as old project debug normally . 

 

hamitiya
hamitiya
ST Employee
May 5, 2026

Could you please try to disable the first "binary" flash and only load the FSBL to see what happens?

You have two kinds of errors:

- ST-Link probe undetected => power-cycle required

- Startup issue => related to flashing procedure

Be aware that setting up breakpoints prior to jump to Application can lead to startup issues as well.

hamitiya_0-1777967816384.png

 

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A
ayaaaaAuthor
Associate II
May 5, 2026

This is what im getting with the latest configuration that you proposed 

ayaaaa_0-1777965719184.png

ayaaaa_1-1777965761790.png

 

Julian E.
Julian E.
Technical Moderator
May 19, 2026

Hi @ayaaaa ,

 

Please let us know if you still have this issue with the ST Edge AI Core 4.0

 

Have a good day,

Julian

​In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question.
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