nrf52832 Peripheral Clock Assignment

RE: nrf52832 Peripheral Clock Assignment

nothingmuchyou — Mon, 25 Jan 2021 15:52:52 GMT

[quote userid="15146" url="~/f/nordic-q-a/53110/nrf52832-peripheral-clock-assignment/290813#290813"]ideally something similar should have been present in the nRF52 PS as well[/quote]

Do you think there will be an update to the documentation?

RE: nrf52832 Peripheral Clock Assignment

Sigurd — Fri, 22 Jan 2021 16:06:11 GMT

Hi,

[quote userid="99363" url="~/f/nordic-q-a/53110/nrf52832-peripheral-clock-assignment/290802#290802"]how do I know who is a Nordic engineer on this forum vs just a customer like me?[/quote]

If you hover your mouse cursor over the username picture/avatar, or click on the username, then Nordic engineers will have this kind of badge:

[quote userid="99363" url="~/f/nordic-q-a/53110/nrf52832-peripheral-clock-assignment/290366#290366"]Where in the product specification does it say where each clock goes??[/quote]

There is no single table for this in the nRF52 PS, in the nRF51 PS we have this table:

ideally something similar should have been present in the nRF52 PS as well.

RE: nrf52832 Peripheral Clock Assignment

nothingmuchyou — Fri, 22 Jan 2021 15:32:08 GMT

Thanks for your help Dmitry. Maybe this next question is silly but how do I know who is a Nordic engineer on this forum vs just a customer like me? It's hard to tell what to take as a spec in the datasheet vs what to take with a grain of salt.

RE: nrf52832 Peripheral Clock Assignment

Dmitry — Thu, 21 Jan 2021 21:39:50 GMT

[quote userid="99363" url="~/f/nordic-q-a/53110/nrf52832-peripheral-clock-assignment/290606#290606"]

PCLK32M is used for I2S and PDM. Anyway you can't control these lines independently.

Could you point me to the place in the product specification that says this?

[/quote]

nRF52832 PS 1.4, pages 441 and 456 (master clock registers)

[quote userid="99363" url="~/f/nordic-q-a/53110/nrf52832-peripheral-clock-assignment/290606#290606"]

Most are running from PCLK16M

Could you also point me to the place in the product specification that says this?

[/quote]

Unfortunately no, but it was mentioned by Nordic engineers many times on this forum, for example here.

RE: nrf52832 Peripheral Clock Assignment

nothingmuchyou — Thu, 21 Jan 2021 19:07:15 GMT

[quote userid="5418" url="~/f/nordic-q-a/53110/nrf52832-peripheral-clock-assignment/290560#290560"] PCLK32M is used for I2S and PDM. Anyway you can't control these lines independently.[/quote]

Could you point me to the place in the product specification that says this?

[quote userid="5418" url="~/f/nordic-q-a/53110/nrf52832-peripheral-clock-assignment/290560#290560"]Most are running from PCLK16M[/quote]

Could you also point me to the place in the product specification that says this?

RE: nrf52832 Peripheral Clock Assignment

Dmitry — Thu, 21 Jan 2021 14:04:41 GMT

Yes, there is no such info in a single place for quick look, only in description of modules that use clock different from PCLK16. LFCLK is mentioned in spec for RTC and WDT, the same is for radio and NFC that require HFXO. Other modules will use either HFINT running on-demand, or HFXO if it's already started. Most are running from PCLK16M, timers can work from PCLK1M when it's sufficient, PCLK32M is used for I2S and PDM. Anyway you can't control these lines independently.

What's really missing is a notice about switching between HFINT and HFXO - while it looks quite clear, many developers are got catched. Because of a difference in frequency, this switching sometimes causes issues especially with UART and PWM.

RE: nrf52832 Peripheral Clock Assignment

nothingmuchyou — Wed, 20 Jan 2021 20:30:07 GMT

This doesn't really answer the original question. Where in the product specification does it say where each clock goes?? I've been looking for awhile.

RE: nrf52832 Peripheral Clock Assignment

ptskyin — Mon, 14 Oct 2019 02:25:10 GMT

Thanks, Dmitry!

RE: nrf52832 Peripheral Clock Assignment

Dmitry — Thu, 10 Oct 2019 12:07:37 GMT

Hi,

LFCLK is used by RTC and WDT, maybe also LPCOMP (if it needs any clock at all). Others use HFCLK.