nRF9161 Getting the high accuracy oscillator (HFXO) outside and sync with other nrf chips?

[schnitzlein]

Question: nRF9161 Getting the high accuracy oscillator (HFXO) outside and sync with other nrf chips?

Basically I want to get the Clock Signal outside on a Pin, is it an option?
How can I achivew this and bring out the Clock Signal?

Goal
I want to use this Clock on another nrf Chip instead of external Clock, just this Clock Signal.


Hopefully someone have good news for me.


kind regards

[Øyvind]

Hello, 

I will come back to you on Monday with an answer. 

Sorry for the inconvenience!

Kind regards,
Øyvind

[schnitzlein]

Hi,

thanks!

I get my hands dirty and get a running High Precsion Clock running.
I used the Clock Control from NRF and play around with NRF Timer.

CONFIG_CLOCK_CONTROL_NRF=y

CONFIG_NRFX_TIMER0=y

It is quite nice and have the timeing scale we need.

---

#include <zephyr/kernel.h>
#include <nrfx_timer.h>
#include <zephyr/drivers/clock_control.h>
#include <zephyr/drivers/clock_control/nrf_clock_control.h>
#include "nrfx_clock.h"

// ...

main() {
// ...

clock_init();

 nrf_timer_task_address_get(timer.p_reg, NRF_TIMER_TASK_START);

 // my test stuff

 if(nrfx_clock_hfclk_is_running() == true){
 LOG_INF("The High precsion clock is running");
 } else {
 LOG_INF("The High precsion clock is not running");

 }
}

---

There is the clock page: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fps_nrf9161%2Fpmu_oscillators.html&anchor=frontpage__fig

And finally I read some topics here in the devzone with "clock" as a tag.
But still I am not clear how to put the clock to an external PIN and read it back on another Board?

I use this sample here: https://github.com/nrfconnect/sdk-nrf/blob/main/samples/peripheral/radio_test/src/main.c#L11 as it was recommended.

But there is no XL1 and XL2 so far I saw ...
XL1 and XL2, XC1 and XC2

So it looks like I have not an option to output and input the clock right ?

greetings

[Øyvind]

Hello

Due to summer vacation period in our technical support team we are lower staffed than normal, this may cause some delays in our answers. Sorry for the inconvenience. 

---

The MIPI RFFE interface is accessible through AT commands ( %XMIPIRFFEDBG) when modem is running the production test image. 

schnitzlein said:

I use this sample here: https://github.com/nrfconnect/sdk-nrf/blob/main/samples/peripheral/radio_test/src/main.c#L11

This sample is not for the nRF91-series. The Radio test sample demonstrates how to configure the radio in a specific mode and then test its performance. It requires our BLE devices for testing. 

Could you please elaborate more on what you trying to achieve? 

Kind regards,
Øyvind

[schnitzlein]

Hello,

thanks for your response!
Sorry for my confusion ... shame on me.

here is my plan:

Actually I was checking all the options in how could I synchronize the clocks between many nrf9161-DK in the first place, for a project there will be similar/same Chipsets used.
They should synchronize with a clock, also the radios on those DK should be synced with a clock.
So a simple transmit scenario at the same time with different setups could be achieved.

I found out that the external clock support for nrf9161-DK is not really an option, no external osszilator input is possible, so far I understand.

But I could maybe test the way out --> fetching the Clock Source from one nrf9161-DK Board and put it with pwm or something else outside on a GPIO and route this/wire this to another nrf9161-DK Board.

This is my plan/scenario I am currently experimenting on.

I found out that for the radio the HFCLK can be used as a source but will be deriving to a LFCLK.
But this is all I know right now.

Maybe you have some input for me?


I am just checking this website, documentation, samples/examples and experiment around with some Code.

greetings

[Øyvind]

schnitzlein said:

But I could maybe test the way out --> fetching the Clock Source from one nrf9161-DK Board and put it with pwm or something else outside on a GPIO and route this/wire this to another nrf9161-DK Board.

The closest I could find to achieve something similar is to use DPPI - Distributed programmable peripheral interconnect and GPIOTE — GPIO tasks and events. You can use our nrfx generic ppi layer that provides the common functionality of PPI and DPPI(nRF53/nRF91) drivers.

There is a small sample available here, showing how to use the nrfx_gpiote, nrfx_gppi and nrfx_timer drivers to implement a simple pulse counter mechanism. This is based on nRF Connect SDK v2.5.2. 

Let me know if that helps to find the right path

Kind regards,
Øyvind