topic Re: How can I disconnect debugger? in i.MX RT Crossover MCUs

How can I disconnect debugger?

davenadler — Wed, 04 Mar 2026 19:24:04 GMT

Problem:

I need to disconnect the debugger and leave the application running.
Simply yanking out the J-Link's USB cable usually crashes my board.
There is a Disconnect button in the debug tool-bar, but it is grayed out.

How can I just disconnect (gracefully) the debugger (and leave the application running happily)? And hopefully then I can power down the J-Link?

Context:

large FreeRTOS application running on imxRT1024.
debugger is working absolutely fine
MCUXpresso IDE v24.9 [Build 25] [2024-09-26] on Windows 10
segger J-Link software version V9.22 (just updated to most recent version)

Re: How can I disconnect debugger?

Gavin_Jia — Thu, 05 Mar 2026 06:35:19 GMT

Hi @davenadler ,

Thanks for your interest in NXP MIMXRT series!

Did your application use semihost? Or did the software reconfigure any SWD-related pins? It's also possible that your hardware caused power supply issues after disconnecting from the debugger. Please help to check this. Alternatively, you can try using serial download mode to directly download the image to the flash memory, then check if it runs correctly.

Because if your debugger correctly programmed the binary file into the flash, it's unlikely that disconnecting from the debugger would cause a crash.

Best regards,
Gavin