11.188 WFE

Wait For Event.

Syntax

WFE{cond}

where:

cond

is an optional condition code.

Operation

This is a hint instruction. It is optional whether this instruction is implemented or not. If this instruction is not implemented, it executes as a NOP. The assembler produces a diagnostic message if the instruction executes as a NOP on the target.

WFE executes as a NOP instruction in ARMv6T2.

If the Event Register is not set, WFE suspends execution until one of the following events occurs:

  • An IRQ interrupt, unless masked by the CPSR I-bit.

  • An FIQ interrupt, unless masked by the CPSR F-bit.

  • An Imprecise Data abort, unless masked by the CPSR A-bit.

  • A Debug Entry request, if Debug is enabled.

  • An Event signaled by another processor using the SEV instruction.

If the Event Register is set, WFE clears it and returns immediately.

If WFE is implemented, SEV must also be implemented.

Architectures

This ARM instruction is available in ARMv6K and above.

This 32-bit Thumb instruction is available in ARMv6T2 and above.

This 16-bit Thumb instruction is available in ARMv6T2 and above.

Non-ConfidentialPDF file icon PDF versionARM DUI0473M
Copyright © 2010-2016 ARM Limited or its affiliates. All rights reserved.