This section describes the basic procedure for transitioning the state of a power domain.
Note: The PD_WKUP 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, y denotes the module domain number):
- Wait for WKUP_PSC0_PTSTAT[x] GOSTAT or
PSC0_PTSTAT[x] GOSTAT to clear to 0. Wait for any previously initiated
transitions to finish before initiating a new transition.
- Set WKUP_PSC0_PDCTL_y[0] NEXT or PSC0_PDCTL_y[0]
NEXT for an ON (1) or OFF (0) transition. NOTE: When WKUP_PSC0_PTCMD[x] GO or
PSC0_PTCMD[x] GO is set to 1 in the next step, the PDCTLx[0] NEXT field of this
power domain and the WKUP_PSC0_MDCTL_y[4-0] NEXT or PSC0_MDCTL_y[4-0] NEXT field
of the module in this power domain are evaluated. Therefore, the
WKUP_PSC0_MDCTL_y[4-0] NEXT or PSC0_MDCTL_y[4-0] NEXT field may be set for
multiple modules before executing this step.
- Set WKUP_PSC0_PTCMD[x] GO or 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 WKUP_PSC0_PTSTAT[x] GOSTAT or
PSC0_PTSTAT[x] GOSTAT to self-clear to 0. The domain is safely in the new state
only after WKUP_PSC0_PTSTAT[x] GOSTAT or PSC0_PTSTAT[x] GOSTAT is cleared to
0.