RE: nRF51822 : enable protection against readback in app doesn't work

Sébastien Despont — Thu, 26 Sep 2013 06:55:05 GMT

Thanks for your quick answer. I have looked on the nrfjprog software and it fits my needs.

P.S. About the Developer Zone editor, it would be great if you could add a live preview of the final render when a question or an anwer is writing.

RE: nRF51822 : enable protection against readback in app doesn't work

Ole Morten — Wed, 25 Sep 2013 16:16:57 GMT

The UICR is a flash-backed register, and as such, it cannot be written like you have done here, you have to enable flash writing in the NVMC first. Flash writing also halts the CPU, so if this happens to be at the same time as a radio event, the softdevice will assert. You should therefore always use the radio notification feature when doing flash writes.

However, a much simpler option is to set this with nrfjprog, and not on run-time. This can be done with the --rbp option:


nrfjprog --help
...
     --rbp <protection_level>                     Sets the desired protection
                             level. Only CR0 or ALL can be used as valid
                             levels. Can be combined with erase operations,
                             reset operations and programming operations.
...

(It is also possible to do a special trick to include such setting in the hex file itself, in which case this will be done automatically on programming. See the uicr_config_example in SDK 4.4.0)

PS: I saw you had problems with the code-tag. We're working on solving that, and the fix will hopefully come tomorrow!