Hi,
How do we fuse the debug port on nRF9160? The purpose is to block all access and the ability to erase all from outside.
This is my understanding:
From debugger as last step in factory:
Set UICR APPROTECT=0 to disable DAP access (non-volatile setting)
Set UICR ERASEPROTECT=0 to disable erase all through CTRL-AP (non-volatile setting)
At each device boot as early as possible:
Set ERASEPROTECT.DISABLE=0 to disable possibilty to enable erase all again
Set ERASEPROTECT.LOCK=1 to disable possibilty to write ERASEPROTECT.DISABLE (strictly not necessary, but a safe guard?)
Is my understanding correct?
A related question:
Thingy91 has a nRF52xx SoC. Is it possible to fuse its debug port in the same way?
BR / Björn