This section describes the basic procedure for transitioning the state of a power domain.
Note: The power domain is always in the ON state when
the device is powered-on, and therefore it is not possible to transition this
domain to the OFF state. Conversely, the other domains are in the OFF or ON
state when the device is powered-on. Transitions between ON and OFF states need
to follow the procedure below. See the device-specific Datasheet and respective
module Technical Reference Manual chapter for any other considerations
especially while turning off the power domain.
The procedure for power domain state transitions
is shown below (x denotes the power domain number):
- Wait for PSC0_PTSTAT[x] GOSTAT or
MCU_PSC0_PTSTAT[x] GOSTAT to clear to 0. Wait for any previously initiated
transitions to finish before initiating a new transition.
- Set PSC0_PDCTL[0] NEXT or MCU_PSC0_PDCTL[0] NEXT for an ON (1) or OFF
(0) transition. NOTE: When PSC0_PTCMD[x] GO or MCU_PSC0_PTCMD[x] GO is set to 1
in the next step, the PDCTL[0]
NEXT field of this power domain and the PSC0_MDCTL[4-0] NEXT or
MCU_PSC0_MDCTL[4-0] NEXT
field of the module in this power domain are evaluated. Therefore, the
PSC0_MDCTL[4-0] NEXT or
MCU_PSC0_MDCTL[4-0] NEXT
field may be set for multiple modules before executing this step.
- Set PSC0_PTCMD[x] GO or MCU_PSC0_PTCMD[x] GO to 1
to initiate the state transition(s). The PSC turns on or off the logic/memory
for that particular domain.
- Wait for PSC0_PTSTAT[x] GOSTAT or
MCU_PSC0_PTSTAT[x] GOSTAT to self-clear to 0. The domain is safely in the new
state only after PSC0_PTSTAT[x] GOSTAT or MCU_PSC0_PTSTAT[x] GOSTAT is cleared
to 0.