case about nRF52 and nRF53 recover discrepancy

[peter.min]

Hi,

1. The customer would like to know which values are configured for which registers of nRF5340 by the following instructions?

nrfjprog --family NRF53 --coprocessor CP_NETWORK --recover
nrfjprog --family NRF53 --recover

2. Compare the instructions in 52 below, what are the differences in the operation of the register?
nrfjprog --family NRF52 --recover

Thank you for all your assistance.
Kind regards,
Peter.Min

[Hieu]

Hi Peter,

Is there any particular reason the customer wants to understand to that level of details?
Also, do you want this to be private, if you are discussing details about your customer?

What the --recover command does is described in the nrfjprog commands documentation:

Erases all user flash memory and disables the readback protection mechanism if enabled.

The nRF5340 Erase All procedure is detailed here: https://docs.nordicsemi.com/bundle/ps_nrf5340/page/ctrl-ap.html#ariaid-title3

Access Port Protection is used to implement readback protection. It is detailed here: https://docs.nordicsemi.com/bundle/ps_nrf5340/page/debugandtrace.html#access_port_protection__tab_app_details_ns

Best regards,

Hieu

[peter.min]

Hi Hieu,

The purpose is to make an offline programming tool

1. It is important that nrfjprog --recover will write a firmware to the chip
2. In this written firmware, what key register operations have been done to disable read protection?

Thank you for all your assistance.
Kind regards,
Peter.Min

[Nguyen Hoan Hoang]

Add the --log then read the log file.  All the steps are in there.

[Hieu]

Hi Peter,

Looking at the nrfjprog logs like Hoang said is one way you can see exactly what registers are written.

Otherwise, the documentation I linked previously shows exactly what register operations have to be done to disable read protection. I won't be able to write better than the documentation.

For the purpose of creating a programmer, you might be interested in this application note: nRF5340 Production Programming (nordicsemi.com)

Hieu