[254] errata

RE: [254] errata

user2111 — Mon, 13 Jun 2022 13:25:51 GMT

From my understanding it may for instance affect sensitivity and blocking. I don't have much more details, since it's not been tested or intended to be used without an FEM.

Best regards,
Kenneth

RE: [254] errata

user108266 — Mon, 13 Jun 2022 12:23:38 GMT

Hi Kenneth !

I have own radio and really should/can program all radio registers with desired values and write own driver for this.

I have some boards with FEM and some without. Looks like it is not so easy to detect GPIO controlled nRF21540.

But for have common FW for both designs, I should have runtime detection if FEM present or not.

How harmful can be case when errata is applied for board where FEM is not present ?

Regards,

Eugene

RE: [254] errata

user2111 — Mon, 13 Jun 2022 12:12:11 GMT

Hi,

You can find in the errata 254 also says at the end: "This workaround is included in nRF Connect SDK 1.7 and later." So the easiest is to update to 1.7 or later to apply the workaround for errata 254:
https://infocenter.nordicsemi.com/topic/errata_nRF52840_Rev3/ERR/nRF52840/Rev3/latest/config_840_254.html

But to answer your questions:

1. This must only be done with designs using FEM. The code snippets itself do check if there is a value at certain memory address, and only apply the workaround in those specific cases, so they should be safe to run on all revisions of the nRF52840, since the codes snippets will have no effect on devices with date code prior to 2139.

2. The first code snippet for all radio modes, the last two code snippets only apply to 802.15.4. Honestly speaking I think applying these workaround to earlier nRF Connect SDK or even nRF5 SDK will be difficult, since typically the radio stacks are precompiled libraries (e.g. softdevice controller) that does not allow direct radio manipulation, but if you are writing your own radio stack, then these lines of codes is something you must implement as described.

[quote user=""]is really no need if RADIO is powered off / on before switching to other radio ?[/quote]

True.

Best reards,
Kenneth