A.7. WFE and WFI standby signals

Table A.6 shows the WFE and WFI standby signals. The value of N is one less than the number of processors in your design.

Table A.6. WFE and WFI standby signals

SignalTypeDescription
EVENTIInput

Event input for processor wake-up from WFE standby mode. When this signal is asserted, it acts as a WFE wake-up event to all the processors in the Cortex-A15 cluster. This signal must be asserted for at least one CLK cycle. See Event communication using WFE and SEV instructions for more information.

EVENTOOutput

Event output. This signal is asserted HIGH for three CLK cycles when any of the processors in the Cortex-A15 cluster executes an SEV instruction. See Event communication using WFE and SEV instructions for more information.

STANDBYWFE[N:0]Output

Indicates if a processor is in WFE standby mode:

0

Processor not in WFE standby mode.

1

Processor in WFE standby mode.

STANDBYWFI[N:0]Output

Indicates if a processor is in WFI standby mode:

0

Processor not in WFI standby mode.

1

Processor in WFI standby mode.

STANDBYWFIL2Output

Indicates if L2 is in WFI standby mode. This signal is active when the following are true:

  • all processors are in standby WFI

  • ACINACTM and AINACTS are asserted HIGH

  • L2 is idle.


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