nRF52 DK segger (PCA10036) not giving option to lock the application code

[Rahul Sahu]

I am using nRF51822 (PTR5518A) with SDK v12 and s130 softdevice. To dump the code I am using nRF52 DK segger (PCA10036). With that I am able to dump the code but there is no option to lock it. I don't have any other segger board to dump the code. Is there any way to enable code locking facility in nRF52 DK segger board ? Or can I enable it through code?

[endnode]

This looks like misunderstanding. Every nRF5x chip you can "lock" against read-back and debugger access. This is what most of the people do once they are done with development and go to production. The only way to bypass it is either hack it (there unfortunately is vulnerability on nRF51 which allows some tricks) or erase the chip completely which will "unlock" it.

Then you say you have PCA10036 but you don't have other SEGGER board. Why would you need it? "Lock" in nrfjprog or nRFgo Studio is of course linked to the nRF5x target chip not to SEGGER J-Link OB fw (that is kind of locked by itself, you can only bootload it and update with other FW image from SEGGER or Nordic...)

[endnode]

If you want to "lock" nRF5x chip then it's easy and you have many options:

• You can write into UICR register from within the FW itself (but you need to write this functionality before you compile and load the FW of course;).
• You can write to UICR over SWD by simple memory access (there is logical address in Reference Manual/Product Specification of each chip).
• You can use specific command of nrfjprog tool which will write into UICR for you (you don't need to look-up addresses and register mapping, tool has it built-in based on chip type/family).
• You can lock the chip when programming through nRFgo Studio (Windows tool with GUI). Same principle as previous case, just a checkbox not a command;)
• Probably other tools and ways possible...