S32K3xx: how to get wakeup source when wakeup from standby

[Jingjing]

Hello:

S32K314:when wakeup from standby mode by kl15,how to get wakeup source is kl15?

5745b：read wakeup source directly from WKPU->WISR.

S32K314: IP_WKPU->WISR_64/IP_WKPU->WISR, when wakeup from standby, the value are all 0x0.

how to read the wakeup source in S32K314?

[lukaszadrapa]

Hi,

if WISR is 0x0, it looks like the device was reset. I would check MC_RGM.DES and MC_RGM.FES registers to check the source of possible reset. Notice that the flags are cleared only by POR, so clear them before entering standby mode.

Regards,

Lukas

[Jingjing]

thank you for reply.

please help to check below question:

1. normal action:enter standby  can not cause reset?

   if enter standby action cause reset, the hardware is design error?

2. WISR/WISR_64 value can keep from enter standby to wakeup?

3. if wakeup from standby cause reset,how to get the exactly wakeup source, for example:kl15 wakeup, and so on.

thank you very much.

[lukaszadrapa]

Hi,
Most of the chip is reset on standby exit. Only the modules in STANDBY domain are not impacted by standby exit and retain their content. Exit from standby mode does not set RGM_DES/RGM_FES flags if the device was woken up by WKPU.
In case of standby mode, the only options to exit the standby mode are:
- MC_RGM functional reset event
- MC_RGM destructive reset event
- WKUP wake-up events
The flags in WISR are kept on standby exit.
If the device is woken up by reset or the device is reset after wake up by WKPU, WISR register will be in reset state, so there's no way to read previous content of WISR anymore. You can only read RGM_DES and RGM_FES register to see what was the source of reset.
Regards,
Lukas

[Jingjing]

if i want to get WISR/WISR_64 valu after wakeup from standby, can give me a solution how to realize it? how to config WISR/WISR_64 value to save on standby domain?

[lukaszadrapa]

I can't see reason for this. Have you confirmed in RGM registers that there was no reset and that there's no code which clears the flags in RGM and in WKPU?

Regards,

Lukas