Andy Green wrote:
> I think there is a bit of confusion here.  "Standby" is a separate issue
> that does not need battery backup on MSP430.  IO_3V3 rail is up during
> standby.  MSP430 will be up during standby.

Not quite :-) PMU.Standby != Linux.suspend

When we suspend, the CPU remains in PMU.Active, and all we do is switch
off some of the regulators we don't need. This is your scenario where
IO_3V3 is active.

However, PMU.Standby really means "no power to the system". (You can
change that to some extent by setting bits in STBYCTL1 and STBYCTL2,
but we don't do that.)

Here's the matrix of states as I understand things:

PMU     CPU     Linux
------- ------- ------------
NoPower off     off
Save    off     off
Standby off     off
Active  SLEEP   suspend
Active  IDLE    on, CPU idle
Active  NORMAL  on, CPU busy

CPU.off means completely unpowered. In CPU.SLEEP, I/O and VDDalive are
powered, core and PLLs aren't, (I'm too lazy to look up whether VDDmop
is powered as well ;-) I guess it is.) CPU.NORMAL has all rails powered.

- Werner

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