Is nrf51 DEVICEID unique?

RE: Is nrf51 DEVICEID unique?

awneil — Fri, 12 Jul 2019 08:35:43 GMT

[quote userid="10130" url="~/f/nordic-q-a/17569/is-nrf51-deviceid-unique"]Reference Manual says the DEVICEID is a "64 bit unique device identifier" [/quote]

It still says it - and it is still wrong!

https://devzone.nordicsemi.com/f/nordic-q-a/49664/deviceid-is-unique---but-is-it-random/198061#198061

RE: Is nrf51 DEVICEID unique?

Hung Bui — Tue, 08 Nov 2016 08:09:28 GMT

Yes, it's correct.

RE: Is nrf51 DEVICEID unique?

pablo — Mon, 07 Nov 2016 15:22:10 GMT

Ok. So it is not unique. Given the FIPS RNG, is it safe to assume that using only DEVICEID[0] would result in a 1/(2^32) risk of collision between two devices?

RE: Is nrf51 DEVICEID unique?

Hung Bui — Mon, 07 Nov 2016 13:52:24 GMT

Hi Pablo,

The DEVICEID is randomly generated using FIPS approved random number generator during production process. There is a slight chance that you have 2 chips with same DEVICEID but the possibility's very small given the high amount number of bits (= 1/(2^64) = 5.42*10^-20) .