The issue where protect is automatically enabled every time the firmware is written

[naya]

Hello,

I have a question regarding a recent issue.

I'm currently developing with the nRF52840 IC or EVM, and I'm facing a problem. Whenever I write firmware to the flash, it seems that the read-protect mode is automatically enabled. This makes development very difficult, as I have to perform recovery mode every time.

There were no such issues with the previous IC.

Could you please help me find a solution? I would greatly appreciate your assistance.

[SwRa]

Hello,

The nRF52840 Rev 3 has APPROTECT enabled by default after every reset or power cycle. This is a security feature designed to protect the device from unauthorized access.

I assume you are using the nRF Connect SDK.. In your project configuration, add the following Kconfig option to disable APPROTECT:
CONFIG_NRF_APPROTECT_LOCK=n

This configuration will ensure that the firmware doesn't lock the access port on boot: https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/security/ap_protect.html#enabling_software_ap-protect_with_confignrfapprotectlock 

Best Regards,

Swathy

[naya]

Hello,

Thank you very much for reviewing the issue. We are also using the nRF Connect SDK, so it will likely be helpful for future use with the 52840. However, the current issue is occurring in a project that uses the nRF52 SDK, version 17.02. I would greatly appreciate it if you could guide me once again on how to resolve this issue within this SDK. Your assistance would be highly appreciated.

Thank you in advance!