topic Re: Need help locking and unlocking an LPC55S28JBD100 chip in LPC Microcontrollers

Need help locking and unlocking an LPC55S28JBD100 chip

CPrice94 — Tue, 07 Feb 2023 21:28:56 GMT

I am working on a project that requires me to know how to lock and unlock an LPC55S28JBD100 microcontroller. I have perused the user guides for the chip itself, the MCUXpresso IDE, the MCUXpresso Secure Provisioning Tool, and the user guide for the J-link probe I am using to connect to and read the flash content.

I am doing this on a development board from NXP for the LPC55S28 microcontroller. When I first got the development board and flashed the chip using the IDE, I had to unlock it by using a J-link command. The command worked and the chip was unlocked, but I need to know how to lock it again to recreate the process.

I would like to be able to write a program to the chip using the IDE, lock it, and then verify it can be unlocked using my J-link probe and the on-board SWD interface.

Re: Need help locking and unlocking an LPC55S28JBD100 chip

Alice_Yang — Wed, 08 Feb 2023 03:07:53 GMT

Hello @CPrice94

What function do you want to lock for lpc55s28? SWD?

Alice

Re: Need help locking and unlocking an LPC55S28JBD100 chip

CPrice94 — Wed, 08 Feb 2023 14:59:03 GMT

Yes, I am wanting to use SWD to read the lpc55s28. I am able to unlock it using the "unlock" command from J-Link Commander, so I know I can unlock it and then read the flash contents using SWD.

So if there is a way to lock the chip against SWD so I can unlock it again that would be the goal.

Thanks.

Re: Need help locking and unlocking an LPC55S28JBD100 chip

Alice_Yang — Mon, 13 Feb 2023 08:13:34 GMT

Hello @CPrice94

Disable SWD can through SOCU_PIN and SOCU_DFLT:

About detail you can refer to UM11126. And there is a demo from our SE team, I attached it for you.

Pay attention, the demo also disabled ISP .

BTW, how do you lock it before your unlock?

Alice