Is UICR really a full 1K flash page?

RE: Is UICR really a full 1K flash page?

Clem Taylor — Thu, 23 Oct 2014 20:20:40 GMT

I am only looking to store manufacturing time data. My question was if it is safe to use the full 1k and if so why does the reference manual only mention the first 256 bytes. I can really use the extra bytes, but don't want to risk manfacture yield as a result.

RE: Is UICR really a full 1K flash page?

Clem Taylor — Thu, 23 Oct 2014 20:07:24 GMT

Yes, the data survived a power cycle. I have not tested the full 1k range, but if to look at that region in gdb the 0xffffffffs stop after 1k.

RE: Is UICR really a full 1K flash page?

Stefan Birnir Sverrisson — Thu, 23 Oct 2014 13:06:01 GMT

The UICR is somewhat special and does not behave as a normal flash page. You can only erase it with two commands (see nRF51 Series reference manual v2.1, NVMC chapter), nrfjprog --eraseall, which erases the UICR and the whole 256kB flash area (softdevice, application and bootloader), or with the command nrfjprog --eraseuicr, which will erase the UICR and code region 1, which is the application and the bootloader, so it is normally not convenient to use as you can not erase it unless erasing everything else.

RE: Is UICR really a full 1K flash page?

azdem — Wed, 22 Oct 2014 11:01:04 GMT

Have you checked whether it is really written to 0x1001200? If some of the address bits are "don't care", it may be written to (and read from) 0x1001000 indeed...