nRF54L15 32Khz XO verify.

[weiliwang]

Hi nRF experts.

Is there any way to output 32khz to gpio? We need to verify the frequency offset of 32khz.

I saw that there is a ppi_trace sample code that seems to solve my problem, but this ppi_trace cannot be compiled on the nRF54L15 platform.
Can you let me know if there is any method that can be verified currently?
Thanks.

[Hung Bui]

Hi Weili,
There is a new feature on the nRF54L that you can output the LKCLK and HFCLK to one of the GPIO pins. 
Please take a look at the GRTC peripheral here: https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/grtc.html#ariaid-title5

The pin for LFCLK (32kHz) is P0.04.

We don't have an example to show this but you can just set the register directly or use the nrf_grtc_clkout_set() function in the nrfx_grtc driver.

[weiliwang]

Hi Hung.

Sorry, this is our first time contacting the nRF platform.
I used the radio_test sample and added the following declaration after clock_init() of the main function. Is this correct?

#include <hal/nrf_grtc.h>
NRF_GRTC_Type NRF_GRTC_regs;
int main(void)
{
	int blink_status = 0;
	int err = 0;

	configure_gpio();

	memset(&NRF_GRTC_regs, 0, sizeof(NRF_GRTC_Type));
	NRF_GRTC_regs.CLKCFG = (0x00000000UL);
	NRF_GRTC_regs.CLKOUT = (0x00000001UL);

	nrf_grtc_clkout_set(&NRF_GRTC_regs,NRF_GRTC_CLKOUT_32K,true);

	err = uart_init();
	if (err) {
		error();
	}

	if (IS_ENABLED(CONFIG_BT_NUS_SECURITY_ENABLED)) {
		err = bt_conn_auth_cb_register(&conn_auth_callbacks);
		if (err) {
			printk("Failed to register authorization callbacks.\n");
			return 0;
		}
	....
	....
	....
	...
}

I didn't see any waveform in P004, only a high level.
Please tell me if I missed any details.

SDK V2.8

nRF54L15 DK board .v0.8.1

[Hung Bui]

Hi Weili,

I will be able to test with the nRF54L board on Monday when I'm back to the office. 
But could you try to configure the pin as output pin in the device tree ? 

[Emil Lenngren]

You can't define your own NRF_GRTC_Type variable. You must use the one that is memory mapped to the actual hardware peripheral: NRF_GRTC.

[weiliwang]

Hi Emil.

Thanks for your suggestion, I have solved this problem.