topic Re: Wakeup Source Recognition after function reset from standby mode. in S32K

Wakeup Source Recognition after function reset from standby mode.

aryandis — Thu, 20 Nov 2025 06:06:21 GMT

Hello NXP,

i am working on sleep wakeup application. and have configured wakeup sleep configuration for standby wakeup.

my query is how i can know wakeup source after function reset from standby wakeup?

Re: Wakeup Source Recognition after function reset from standby mode.

aryandis — Thu, 20 Nov 2025 06:33:56 GMT

Since i am using Autosar stack and it is require to have wakeup sources ID.

how to config WISR/WISR_64 value to save on standby domain after function reset?

can you help me how do i configure it.

Re: Wakeup Source Recognition after function reset from standby mode.

Julián_AragónM — Thu, 20 Nov 2025 22:28:12 GMT

Hi @aryandis,

After wake-up, you can read WISR/WISR_64 registers to identify which source caused wake-up. You do not need to save them to Standby RAM or use fast standby exit, as the values are kept intact after a standby exit.

Mcu_GetResetReason() returns if the previous reset was standby exit, or any other reset else (HW, SW, WDG, etc.…), however there are no APIs for wake-up source.

For reading the registers, just make sure the main routine does not clear the registers before saving them, and keep in mind that if a falling edge is used, pad keeping must be enabled (refer to this community post: Solved: WISR_64 no correct after wakeup from fast standby mode on S32K312 - NXP Community).

You can refer to the low power examples from community:

The MCAL layer also provides EcuM module which reports wake-up source, however, the RTD package only provides stub files for EcuM, intention is to use them as a reference and can be modified/replaced depending on the application needs.

Best regards,
Julián

Re: Wakeup Source Recognition after function reset from standby mode.

aryandis — Mon, 24 Nov 2025 08:27:28 GMT

Is Icu_GetInputState API needs to call after wakeup to read WISR value?

Re: Wakeup Source Recognition after function reset from standby mode.

Julián_AragónM — Tue, 25 Nov 2025 17:31:33 GMT

Hi @aryandis,

Yes, this will call Wkpu_Ip_GetInputState() and return TRUE if the corresponding WKPU channel is set and then it will clear the flag.

After wake-up (standby exit), the NVIC registers will be reset to default (disable all of peripheral interrupts), but the value of WKPU registers and previous state is still kept. So, after wake-up, if you call Platform functions to enable interrupt for wake-up (configure NVIC_ ISER for WKPU_IRQn) then your program will jump into wake-up interrupt function, and you can determine which the wake-up source occurred.

If you don't call Platform functions to enable interrupt for wake-up in run mode after wake-up, you can call Wkpu_Ip_GetInputState() function to determine the wake-up source.

You can also read the registers directly after wake-up.

Best regards,
Julián

Re: Wakeup Source Recognition after function reset from standby mode.

aryandis — Wed, 26 Nov 2025 06:33:03 GMT

ok, one query have.

I have enabled the EcuM module and calling Icu_Checkwakeup() inside EcuM_CheckWakeup(). But the problem is we are not able to trigger the EcuM_CheckWakeup when there is a ICU Wakeup Event. (because the channel state is RUNNING which is not allowing to call EcuM_CheckWakeup())

how i should trigger EcuM_CheckWakeup()?

Can i make same wakeup pin as a ISR and there i can call EcuM_CheckWakeup()->Icu_CheckWakeup() and set Bit status as WAKEUP_STATE -> call to EcuM_SerWakeupEvent() ?

if i can make as a ISR then how i cane make?

Re: Wakeup Source Recognition after function reset from standby mode.

aryandis — Thu, 27 Nov 2025 11:09:48 GMT

i have debug the same issue and found the EcuM_Checkwakeup was not called because of ICU_CurrentMode as ICU_NORMAL_MODE set as a begning of Icu_Init after standby wakeup for warm reset.

How do i do this so after wakeup EcuM_Cehckwakeup will call?

Re: Wakeup Source Recognition after function reset from standby mode.

Julián_AragónM — Thu, 27 Nov 2025 22:35:41 GMT

Hi @aryandis,

Sorry, you are right. Calling Icu_Init() function will clear interrupt flag before calling Platform function and change current mode to ICU_NORMAL_MODE. So, you can't call Icu_Init() before. This seems like a driver limitation. Let me ask the internal team for some feedback.

Also, inside the Icu_GetInputState() function uses global variables that needs to be initialized by Icu_Init() function. In this situation, I think you can call Wkpu_Ip_GetInputState() function to check and clear status of WISR or WISR_64, or, read them directly.

Best regards,
Julián

Re: Wakeup Source Recognition after function reset from standby mode.

aryandis — Fri, 28 Nov 2025 10:33:10 GMT

Hi Julian_AragonM can you please once with team regarding Icu_Init() change current mode to ICU_NORMAL_MODE after standbywakeup , how i can do avoid this?

Re: Wakeup Source Recognition after function reset from standby mode.

Julián_AragónM — Tue, 02 Dec 2025 15:44:06 GMT

Hi @aryandis.,

Icu NORMAL mode should not prevent servicing wakeup source. Can you share the code part where Icu is preventing EcuM check wakeup? I can see Icu_CheckWakeup() calls it regardless of ICU mode.

I've also received a response from the internal team:

1. As you already know, Icu module doesn't provide functions that can check wakeup source directly at the MCAL layer. Icu will transfer wakeup source information to EcuM module, and this module will check wakeup source. In RTD driver, EcuM is a stub module, intention is to use them as a reference and can be modified/replaced depending on the application needs.

You can follow Specification of ECU State Manager:

2. In Icu configuration, when user enable "IcuWkpuStandbyWakeSupport" then Icu_Init() will not clear WISR flags.

In your project, to check wakeup source in the Wkpu_Ip layer, you can refer to the below code:

When call Platform_Init(NULL_PTR); before Icu_Init(), I saw that somehow the WISR flags were erased. So, I called this function after Icu_Init() function.

Best regards,
Julián

Re: Wakeup Source Recognition after function reset from standby mode.

aryandis — Wed, 03 Dec 2025 05:17:55 GMT

wakeup source is working and Icu_ReportEvent is coming after wakeup but due to Icu_CuurentMode varaible get init to ICU_NORMAL_MODE from Icu_Init() EcuM_CheckWakeup not calling.

EcuM_CheckWakeup is being called from Icu_ReportwakeupAndOverFlow ICU driver.

Since Icu_ReportwakeupAndOverFlow have condtion checking for variable Icu_CuurentMode to ICU_MODE_SLEEP macro.

Re: Wakeup Source Recognition after function reset from standby mode.

Julián_AragónM — Wed, 03 Dec 2025 22:30:42 GMT

Hi @aryandis,

Icu_CheckWakeup() is the public AUTOSAR ICU API meant to be called (typically by EcuM) after a wakeup to let ICU verify the source and then notify EcuM if it’s valid. It doesn’t depend on the driver being in SLEEP mode.

Icu_ReportWakeupAndOverflow() is internal to the RTD and non-AUTOSAR, it bundles the logic to report a wakeup (and any overflow) immediately from interrupt context.

I suggest, after a wakeup, let Icu_Init() set NORMAL (ensuring WKPU flags persist with IcuWkpuStandbyWakeupSupport = true) and then call Icu_CheckWakeup() with your mapped EcuM wakeup source(s). This works even though Icu_CurrentMode is NORMAL.

Best regards,
Julián

Re: Wakeup Source Recognition after function reset from standby mode.

aryandis — Thu, 04 Dec 2025 04:52:09 GMT

Yes Correct. and Icu_CheckWakeup() will be called from EcuM_CheckWakeup which i have maped. and EcuM_CheckWakeup is getting called form Icu_ReportWakeupAndOverflow API in RTD, which will have condition to check SLEEP_MODE. how EcuM_CheckWakeup trigger without SLEEP_MODE.

or shall i call EcuM_Checkwakeup from ISR is it?

This is snapshot from RTD 3.0.0

Re: Wakeup Source Recognition after function reset from standby mode.

Julián_AragónM — Thu, 04 Dec 2025 20:04:47 GMT

Hi @aryandis,

The way I see it, there are two options:

1. Call EcuM_Checkwakeup() after Standby exit, but before EcuM state machine moves to RUN. This will process the wakeup sources during standby. If the wakeup source is valid, ECU is returned to RUN state.

This is found in the Specification of ECU State Manager:

2. Call it through ISR context, which will service the wakeup source immediately.

Best regards,
Julián