[NRF52832] APPROTECT permanently enabled. Cannot attach to RTT service.

RE: [NRF52832] APPROTECT permanently enabled. Cannot attach to RTT service.

Kenneth — Wed, 20 Oct 2021 13:00:48 GMT

I can't really think of anything, I suggest to keep trying to see if you can find the culpit. There should be a new v10.15 out soon (eta. next week) which might be worth trying out also when available. Let me know if you do new discoveries.

Kenneth

RE: [NRF52832] APPROTECT permanently enabled. Cannot attach to RTT service.

j4cekc1dz — Wed, 20 Oct 2021 09:17:27 GMT

Hello Nordic Crew,

could you please check your the latest versions of nrfjprog.
In my case everything works fine with version below 10.12.0.

"Writing image to disable ap protect." - nrfjprog which prints this string seems to be affected but not with all nordic's chip but for sure with nRF52832 QFAA G1.

BR, Jacek

RE: [NRF52832] APPROTECT permanently enabled. Cannot attach to RTT service.

Kenneth — Tue, 12 Oct 2021 13:48:37 GMT

Make sure to download the latest nrf command line tools:
https://www.nordicsemi.com/Products/Development-tools/nrf-command-line-tools/download

Then the only thing you should need to do is execute 'nrfjprog --recover' one time, this should disable approtect in UICR by writing 0x5A to the APPROTECT register in UICR:
https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/uicr.html#register.APPROTECT

After that the system files should handle the APPROTECT in nrf52_handle_approtect(), which simply set:

/* Load APPROTECT soft branch from UICR.
If UICR->APPROTECT is disabled, POWER->APPROTECT will be disabled. */
NRF_APPROTECT->DISABLE = NRF_UICR->APPROTECT;

Best regards,
Kenneth

RE: [NRF52832] APPROTECT permanently enabled. Cannot attach to RTT service.

j4cekc1dz — Tue, 12 Oct 2021 09:21:51 GMT

FYI, I tested software with NRF_UICR->APPROTECT = UICR_APPROTECT_PALL_HwDisabled as well and APPROTECT is still enabled.