RE: How to output 12.288MHz MCLK with nRF5340 Audio

AHaug — Mon, 15 Jul 2024 08:34:31 GMT

Hi again,

Here's some more information from the Audio team w.r.t your questions

Since the MCLK request by customer is 12.288MHz

that is the maximum output rate which nRF5340 MCLK can achieve
so we should enable "bypass" mode. And the MCLK will just output the clock from the internal clock source directly

This exaplained why customer found there's no waveform once if the bypass mode is disabled.

[quote user=""]a) Is there a range in which mck_setup can be set?[/quote]

If you customer would like to use 12.288MHz for MCLK, then we have to use bypass mode, and MCKFREQ will be ignore
Ref:

[quote user=""]b) Why does synchronization not work when using the bypass function?[/quote]

We would need device logs to be able to say anything regarding this. See https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-2-debugging/ for more information about how to debug and get out logs

[quote user=""]c) Please tell me the range in which the I2S MCLK can be output on the nRF5340[/quote]

The maximum MCK frequency is 12.288MHz

Additionally we strongly recommend that you use NCS 2.7.0 instead of NCS 2.5.0.

Kind regards,
Andreas

RE: How to output 12.288MHz MCLK with nRF5340 Audio

AHaug — Thu, 11 Jul 2024 12:56:22 GMT

Hi,

From what I can see you've asked some of the same questions in https://devzone.nordicsemi.com/f/nordic-q-a/112559/about-nrf5340-audio-synchronization, i.e the one about synch.

As Amanda has written, we need logs to be able to state anything as to why it does not work, so you will have to set up logging in some way, either over RTT, USB or fix the UART issues in other ways.

Regarding the other questions, have you seen https://docs.nordicsemi.com/bundle/nrfx_3.5.0/page/drivers/i2s/hal.html?

Kind regards,
Andreas