Wait For Interrupt with Timeout is a hint instruction that indicates that the PE can enter a low-power state and remain there until either a local timeout event or a wakeup event occurs. For more information, see Wait For Interrupt.
As described in Wait For Interrupt, the execution of a WFIT instruction that would otherwise cause entry to a low-power state can be trapped to a higher Exception level. See:
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WFIT <Xt>
if !HaveFeatWFxT() then UNDEFINED; integer d = UInt(Rd); SystemHintOp op; case op2 of when '000' op = SystemHintOp_WFET; when '001' op = SystemHintOp_WFIT; otherwise // Do nothing
bits(64) operand = X[d]; integer localtimeout = UInt(operand); if Halted() && ConstrainUnpredictableBool(Unpredictable_WFxTDEBUG) then EndOfInstruction(); case op of when SystemHintOp_WFET Hint_WFE(localtimeout, WFxType_WFET); when SystemHintOp_WFIT Hint_WFI(localtimeout, WFxType_WFIT); otherwise // Instruction executes as NOP
Internal version only: isa v33.11seprel, AdvSIMD v29.05, pseudocode v2021-09_rel, sve v2021-09_rc3d ; Build timestamp: 2021-10-06T11:41
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