Power Control

disabled and finish with a Data Synchronization Barrier operation. When all the state of the processor is saved the processor executes a WFI instruction. The STANDBYWFI signal is asserted to indicate that the processor can enter Shutdown mode.

10.2.5Communication to the Power Management Controller

You can use a Power Management Controller (PMC) to control the powering up and powering down of the processor. The communication mechanism between the processor and the PMC is

amemory-mapped controller that is accessed by the processor performing Strongly-Ordered accesses to it.

The STANDBYWFI signal from the processor informs the PMC of the powerdown mode to adopt.

The STANDBYWFI signal can also signal that the processor is ready to have its power state changed. STANDBYWFI is asserted in response to a WFI operation.

ARM DDI 0363E

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ARM r1p3, R4F manual Communication to the Power Management Controller