Function sam4l::pm::deep_sleep_ready [−] [src]

pub fn deep_sleep_ready() -> bool

Determines if the chip can safely go into deep sleep without preventing currently active peripherals from operating.

We look at the PM's clock mask registers and compare them against a set of known masks that include no peripherals that can't operate in deep sleep (or that have no function during sleep). Specifically:

HSB may only have clocks for the flash (and PicoCache) and APBx bridges on.
PBA may not have any clocks on.
PBB may only have clocks for the flash and HRAMC1 (also flash related) on.
PBC and PBD may have any clocks on.

This means it is the responsibility of each peripheral to disable it's clock mask whenever it is idle.

We also special case GPIO (which is in PBCMASK), and just see if any interrupts are pending through the INTERRUPT_COUNT variable.