topic Code loaded onto MCXN546VKLT will not run in MCX Microcontrollers

Code loaded onto MCXN546VKLT will not run

DBML — Fri, 23 Jan 2026 06:34:02 GMT

I follow the same basic procedure to create a project for the MCXN947 on the FRDM board and initialize and assert the P2_0 pin. It loads and performs as expected. Following the exact same procedure for a. MCXN546 project and selecting the VKLT variant of chip, the code does not run on our platform. I have checked the boot condition of the processor on our board and it appears good.

I am able to use ISP with our board with no issues. Just cannot get it to run basic code.

AI searching talks about corrupting CMPA or CFPA regions of flash causing rom to decide to not boot our code. AI also mentions to look for flash config in startup, but in my exploring sdk and created projects, I cannot see any details of flash config.

Considering this version of part does not have BOOT_MODE pins, how do we ensure that the system will run with our loaded code.

Note that I have confirmed all power conditions and that the RESET_B appears to transition properly on power up.

Re: Code loaded onto MCXN546VKLT will not run

Harry_Zhang — Fri, 23 Jan 2026 08:45:13 GMT

Hi @DBML

I think you can try to download the MCXN546 chip SDK.

And create a project.

Harry

Re: Code loaded onto MCXN546VKLT will not run

DBML — Fri, 23 Jan 2026 16:53:04 GMT

I have of course created my project from the correct SDK and have selected the correct processor package (VKLT). The target board I am loading using blhost - do not have general access to the debugger. Developed functionality using evk and then plan is to port code to target processor and load direct.

Cannot get a simple project, toggling GPIO to execute on target.

Any other suggestions - again, all examples seem to be centered around devices that have access to BOOT0 and BOOT1 pins, this package does not have those pins.

Re: Code loaded onto MCXN546VKLT will not run

Harry_Zhang — Mon, 26 Jan 2026 07:19:42 GMT

Hi @DBML

I think you can refer to this.

How to program MCX N series internal flash through ISP

As you previously described, cmpa and cfpa can also be configured in SEC tools.

MCUXpresso Secure Provisioning Tool | NXP Semiconductors

Harry

Re: Code loaded onto MCXN546VKLT will not run

DBML — Thu, 29 Jan 2026 20:42:59 GMT

Harry,

Thanks, I will review and try. I was travelling on Tuesday, thus slow reply.

Yesterday I tried to connect with MCU Link. Can connect and identify the MCU, but will not load code and execute from debugger. Going to explore this more as well as trying to load basic app reviewing the referenced materials above

Re: Code loaded onto MCXN546VKLT will not run

DBML — Thu, 29 Jan 2026 20:46:46 GMT

I wanted to confirm the startup power of the device. You can see from attached that the power up sequence is as expected.

Yellow trace - 3.3 V from external LDO
Pink trace - 1.0V from internal LDO VDD_CORE
Blue trace - RESET_B line

As you can see, the VDD_CORE is essentially stable when the MCU releases the RESET_B line and allows to go high through our pullup.

Startup power sequence

Re: Code loaded onto MCXN546VKLT will not run

Harry_Zhang — Mon, 02 Feb 2026 08:19:34 GMT

Hi @DBML

Based on the oscilloscope waveforms you provided, I think power‑up sequence is behaving as expected and is fully aligned with the POR requirements in the datasheet.

Harry

Re: Code loaded onto MCXN546VKLT will not run

DBML — Mon, 23 Feb 2026 20:05:56 GMT

I have loaded the chip SDK for the 546 and created project I believe correctly.

Note, last week I decided to purchase and populate board with the MCXN947VKLT, worked right off the bat with my base schematic, etc. I did not need to change anything.

Unfortunately 947 is not a solution for me as in this package, USB HS does not exist (seems odd to loose USB HS in your highest end part). I cannot seem to source anywhere the MCXN547VKLT (wonder if this is cause we are all having problems with the 546).