Using 16MHz SPIM on nRF5340-PDK

RE: Using 16MHz SPIM on nRF5340-PDK

Sigurd — Wed, 17 Jun 2020 12:28:36 GMT

[quote user="DTurnbow"]Is there a sample program that uses nrfx_clock_divider_set()?[/quote]

I don't see any sample code that uses this (as of today).

[quote user="DTurnbow"]Are there only some pins that allow extra high drive?[/quote]

Correct. Some pins may not support every drive configuration. See this chapter: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fps_nrf5340%2Fchapters%2Fpin.html

RE: Using 16MHz SPIM on nRF5340-PDK

DBT — Tue, 16 Jun 2020 13:05:49 GMT

Thanks Sigurd.

Both these hints were helpful.

Is there a sample program that uses nrfx_clock_divider_set()? When I tried to use it I got some build errors so I ended up using the NRF_CLOCK_NS->HFCLKCTRL code directly.

I switched to SPIM4 and the dedicated SPIM4 pins and was able to get it to work. It looked like I might need to setup the SPI pins to use high drive instead of standard drive for 16MHz operation.

I noticed that the datasheet mentions there is an extra high drive option as well, but when I tried to set the PIN_CNF[] register to use extra high drive it didn't work (at least in SES). Are there only some pins that allow extra high drive?

(I tried to set PIN_CNF[8] to 0x00000B01)

RE: Using 16MHz SPIM on nRF5340-PDK

Sigurd — Mon, 15 Jun 2020 14:50:31 GMT

[quote user=""]On a non-secure build, this causes some kind of repeating reset. Can you tell me why?[/quote]

Try using NRF_CLOCK_NS, and not NRF_CLOCK_S

Note that we have a function called nrfx_clock_divider_set() for this. https://github.com/nrfconnect/sdk-hal_nordic/blob/v1.3.0-rc1/nrfx/drivers/src/nrfx_clock.c#L400

What SPI MASTER instance are you using ? Note that only SPI master 4 is high-speed. See this link.