Kinetis MicrocontrollersのトピックRe: K82: TRNG in low power mode

K82: TRNG in low power mode

EugeneHiihtaja — Tue, 04 Dec 2018 08:16:23 GMT

Hi !

Have it sense to completely disable/deinit TRNG and LTC in low power mode LLS3 for have lower power consumption ?

Looks like initialise TRNG take quite long time and power saving difficult to measure.

Can it have some impact for LLS3 mode if some other peripherals are disabled explicitly ?

It might help for avoid false wakeup or hardfault/crashes.

Regards,

Eugene

Re: K82: TRNG in low power mode

jingpan — Wed, 05 Dec 2018 05:38:33 GMT

Hi Eugene,

Like other pure digital module, LTC and TRNG have clock gate, but they don't have power switch. So, they can't be power off at LLSx state.

Which peripherals do you think may impact system if it is disabled explicitly in LLS3 mode?

Regards,

Jing

Re: K82: TRNG in low power mode

EugeneHiihtaja — Wed, 05 Dec 2018 07:53:50 GMT

Hi Jing !

Yes this is exact question what peripherals should be disabled explicitly or some other way for have lower power consumption than default way.

Some GPIO lines should be set to Z-state or to low state for avoid leakage but situation with other peripherals is not clear.

Regards,

Eugene

Re: K82: TRNG in low power mode

jingpan — Thu, 06 Dec 2018 03:26:33 GMT

Hi,

I think besides IO pin, you needn't care about most of peripherals power. Their clock source will be gated at that time. Unlike some other MCU, you'll find that there is rarely peripheral power switch bit. Only those one whose status is option at VLLx you should take care.

AN4503 explained Kinetis power management. You can also read chapter 5 in KURUG.pdf.

Regards,

Jing