nRF5340 memory transaction completion state for clock frequency transition

[responsible_duck]

We want to be able to toggle between 128 MHz and 64 MHz on our nRF5340 based custom board depending on whether our audio pipeline is in process or not. However, a note in the Errata states that we need to ensure all memory transactions are completed before switching the frequency. Is there a straightforward to check all transactions are complete instead of keeping track of everything?

Ref: https://docs.nordicsemi.com/bundle/errata_nRF5340_EngA/page/ERR/nRF5340/EngineeringA/latest/anomaly_340_4.html

Also the instructions state to run these commands:

*(volatile uint32_t *)0x5084450C= 0x4040;
*(volatile uint32_t *)0x50026548 = 0x40;
*(volatile uint32_t *)0x50081EE4 = 0x4D;
NRF_CLOCK_S.HFCLKCTRL = 0;

But it looks like 

nrfx_clock_divider_set(NRF_CLOCK_DOMAIN_HFCLK, NRF_CLOCK_HFCLK_DIV_1);

does the job?

Thanks

[Sigurd]

Hi!

The errata you are linking to is for nRF5340 Engineering A. It's fixed for nRF5340 Revision 1. So you are not affected by this errata.

[responsible_duck]

Thank you!