Application core clock frequency configuration

[MartaOp]

Hi, 

I tried to configure application core frequency from 128 MHz to 64 Mhz using thee function:

nrfx_clock_divider_set(NRF_CLOCK_DOMAIN_HFCLK,NRF_CLOCK_HFCLK_DIV_2);

but I've got an error:  "This code is not supposed to be compiled when neither POWER nor CLOCK is enabled."

 

I've checked on the forum and I found this thread: 

https://devzone.nordicsemi.com/f/nordic-q-a/62533/using-16mhz-spim-on-nrf5340-pdk

The author mentioned that he set the clock configuration directly - How can I do that without throwing the error?

Thanks, 

Marta

[JONATHAN LL]

Hi Marta,

I think the NRFX_CLOCK_ENABLED needs to be set to use the function.
Try setting this CONFIG_COMPILER_OPT="-DNRFX_CLOCK_ENABLED" in the prj.conf.

Regards,
Jonathan

[MartaOp]

Hi Jonathan, 

I've checked it and after changing only this one line I've got:

 undefined reference to `nrfx_clock_divider_set'

I attached the  #include <nrfx_clock.h> library but it's not finding it. 

Is there any other way to set it up?

Thanks,

Marta

[JONATHAN LL]

Hi, 
Check to se if this fixes the problem:

CONFIG_COMPILER_OPT="-DNRFX_CLOCK_ENABLED=1"

and if there are some problems down the line with non-secure/secure then this might help:

CONFIG_COMPILER_OPT="-DNRF_CLOCK=NRF_CLOCK_NS -DNRFX_CLOCK_ENABLED=1"

Regards,
Jonathan

[MartaOp]

Hi Jonathan,

Unfortunately, non of those configuration works. Just to clarify:

- I'm using secure build so I've changed the CONFIG_COMPILER_OPT="-DNRF_CLOCK=NRF_CLOCK_NS -DNRFX_CLOCK_ENABLED=1" to CONFIG_COMPILER_OPT="-DNRF_CLOCK=NRF_CLOCK_S -DNRFX_CLOCK_ENABLED=1" but neither works

- Should nrfx_clock_divider_set(NRF_CLOCK_DOMAIN_HFCLK,NRF_CLOCK_HFCLK_DIV_2); be the first function in main or maybe it should be somewhere else?

I still get "undefine reference" so I tried code:

NRF_CLOCK_NS.HFCLKCTRL = CLOCK_HFCLKCTRL_HCLK_Div1 << CLOCK_HFCLKCTRL_HCLK_Pos;

There is some parenthesis missing: "expected identifier or '(' before 'NRF_CLOCK_Type'
1> ../src/main.c:30:1: note: in expansion of macro 'NRF_CLOCK_NS'"

 

Thanks, 

Marta

[JONATHAN LL]

Hi

Have you seen this post? https://devzone.nordicsemi.com/f/nordic-q-a/59697/nrf5340---how-to-change-clock-freq-of-app-core-on-the-fly

For reference hare is a link to the Clock Changing frequency errata referenced in the mentioned post, link.

I will try to reproduce the scenario myself or se if any colleagues have had a similar issue and get back to you.

Regards,
Jonathan

[MartaOp]

Hi Jonathan,

Unfortunately, when I tried with this solution I've got this error:

Thanks, 

Marta

[MartaOp]

Hi Jonathan,

Do you have any update?

Thanks, 

Marta

[JONATHAN LL]

Sorry for the late reply Marta,

Could you provide some of the code from your main.c file and the functions line 11 to 46. 
If you dont want to share the code we can make this a private case.

Regards,
Joanthan