topic Re: Re: LLS with two wakeup sources in Kinetis Microcontrollers

LLS with two wakeup sources

mathiasbucher — Tue, 12 Aug 2014 13:15:37 GMT

Hi All

I'm trying to implement the LLS mode on my MK22FX512VLH with two wakeup sources: CMP0 and CMP1. Unfortunately, only CMP0 wakes up the MCU, CMP1 has no effect. Does anyone know why?

If I enable only CMP0 or CMP1, it works.

Regards,

Mathias

Re: LLS with two wakeup sources

Hui_Ma — Thu, 14 Aug 2014 07:20:08 GMT

Hi, Mathias,

Any wake up source of LLWU with interrupt happens, it will wake up the core from LLS mode. The related CMP interrupt flag and LLWU interrupt flag will set accordingly.

The LLWU interrupt must not be masked by the interrupt controller to avoid a scenario where the system does not fully exit stop mode on an LLS recovery.

Wish it helps.
best regards
Ma Hui

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Re: LLS with two wakeup sources

mathiasbucher — Tue, 19 Aug 2014 07:45:45 GMT

Hi Hui,

As I answered you by mail, all flags (CMP0 and CMP1 flag in LLWU_F3, CMP0 & CMP1 & LLWU flag in NVIC) are cleared in LLWU interrupt routine.

What does "LLWU interrupt must not be masked by the interrupt controller" exactly mean? How do I have to route the LLWU interrupt, if it must not be masked by NVIC?

Best regards,

Mathias

Re: Re: LLS with two wakeup sources

Hui_Ma — Wed, 20 Aug 2014 09:00:20 GMT

Hi Mathias,

I do a test with TWR-K21F120M boar (similar with K22 120MHz product) and both CMP0 and CMP1 could wake up core from LLS low power mode.

Please check attached code for more detailed info.

Wish it helps.
best regards
Ma Hui