Hello,
We have a custom board with nrf5340 (we are using ncs2.6.0). We are using CPUAPP, CPUNET, and MCUBoot. When we use the Nordic nrf5340 devkit, it works fine and when it locks up we are able to recover the CPUAPP and CPUNET with “nrfjprog –recover” and “nrfjprog --recover --coprocessor CP_NETWORK” respectively. However, when we put the same build that is running on the Nordic nrf5340 (with CPUAPP, CPUNET, and MCUBoot) on the custom board, the board locks up after flashing the build (see attached screenshot). The difference is that the nrf5340 devkit has DC/DC converters while our custom board uses a voltage regulator. In our build we disable the DC/DC converter with these commands:
# Disable DCDC
CONFIG_BOARD_ENABLE_DCDC=n
CONFIG_BOARD_ENABLE_DCDC_APP=n
CONFIG_BOARD_ENABLE_DCDC_NET=n
CONFIG_BOARD_ENABLE_DCDC_HV=n
We noticed that this lock up issue happens when we enable the MCUBoot in our build. When we researched, we found that the issue might be the APPROTECT feature.
- Is there something we can do to prevent this lock up issue from happening?
- Is there a way (HW/SW) to unlock these custom boards?
- Is there a way to disable the APPROTECT? These configurations did not help: https://docs.nordicsemi.com/bundle/ncs-2.9.2/page/nrf/security/ap_protect.html
Thank you in advance.
