Flash protection nrf52840 SDK: 14.0.0

[VoidGreen]

I am trying to implement a bootloader with rewrite protection on nrf52840 with SDK: 14.0.0. But it seems that there is no flash write protection registers in nrf52840. So is there a way to implement a flash rewrite protection?

Thanks.

[Sigurd]

Hi,

The BPROT peripheral that is found in the nRF52832, has been replaced with the ACL peripheral on the nRF52840. ACL works similar to the BPROT(erase/write protection), but also adds support for protection against reading the flash.

You can find more information about the ACL here.

[Sigurd]

The UICR register does not behave as normal flash. After it have been written, you have to reset the chip for it to take effect. Erasing UICR is not done as with normal flash, UICR can be erased using the ERASEUICR register, or in a operation where the whole flash is erased(ERASEALL register).

See this page for more information.