Chip Startup Sequence

RE: Chip Startup Sequence

Håkon Alseth — Wed, 04 Mar 2026 09:45:20 GMT

Hi,

Unfortunately, there is no yaml-bindings for "nordic,nrf-pofcon", so that snippet will not work.

I would recommend that you manually enable CONFIG_NRFX_POWER=y and include the appropriate header, then call "nrfx_power_pof_init(..)" with your wanted configuration and evt handler.

Kind regards,

Håkon

RE: Chip Startup Sequence

Jing Luo — Wed, 04 Mar 2026 02:21:13 GMT

Hi，
I encountered some issues enabling POFCON in NCS. Although I added the following configuration in the dts and it appears to be effective in output/zephyr.dts, during debugging I observed that the register did not take effect. Are there any required .config settings or other considerations I need to be aware of?

regulators: regulator@120000 {
	compatible = "nordic,nrf54l-regulators";
	reg = < 0x120000 0x1000 >;
	status = "okay";
	#address-cells = < 0x1 >;
	#size-cells = < 0x1 >;
	vregmain: regulator@120600 {
		compatible = "nordic,nrf5x-regulator";
		reg = < 0x120600 0x1 >;
		status = "okay";
		regulator-name = "VREGMAIN";
		regulator-initial-mode = < 0x1 >;
	};
	pofcon: pofcon@120530 {
		compatible = "nordic,nrf-pofcon";
		reg = < 0x120530 0x5 >;
		status = "okay";
		pofcon-name = "POFCON";
	};
};

debug record:

Kind regards,

Jing

RE: Chip Startup Sequence

Håkon Alseth — Mon, 02 Mar 2026 09:51:00 GMT

Hi,

[quote user=""]The startup sequence during a power ramp-up (increasing voltage).[/quote]

Please see here:

https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/_tmp/nrf54l15/autodita/RESET/parameters.startup_time.html

[quote user=""]The voltage threshold that triggers a reset during a power ramp-down (decreasing voltage).[/quote]

Brown-out reset (BOR) voltage levels is mentioned here:

https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/_tmp/nrf54l15/autodita/REGULATORS/parameters.power_fail.html

[quote user=""]The time from when the core starts until Flash operations or access is available during the startup phase.[/quote]

Once the system is executing its very first instruction; you are powered up.

Please see here: https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/_tmp/nrf54l15/autodita/CPU/parameters.cpu_wakeup_time.html

[quote user=""]If the Power-Fail Comparator (POF) is configured, the time from when the core starts until the POF becomes effective during the startup phase.[/quote]

The POF needs to be configured from the cpu, ie. you will need to have a running system in order to configure POF.

Kind regards,

Håkon