Base Instructions | SIMD&FP Instructions | SVE Instructions | SME Instructions | Index by Encoding | Shared Pseudocode | Proprietary Notice

## WFET

Wait For Event 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. Wakeup events include the event signaled as a result of executing the SEV instruction on any PE in the multiprocessor system. For more information, see Wait For Event mechanism and Send event.

As described in Wait For Event mechanism and Send event, the execution of a WFET instruction that would otherwise cause entry to a low-power state can be trapped to a higher Exception level.

### System
(FEAT_WFxT)

31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
1 | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | Rd

####

WFET <Xt>

if !HaveFeatWFxT() then UNDEFINED; integer d = UInt(Rd);

### Assembler Symbols

<Xt> | Is the 64-bit name of the general-purpose source register, encoded in the "Rd" field.

### Operation

integer localtimeout = UInt(X[d, 64]); if Halted() && ConstrainUnpredictableBool(Unpredictable_WFxTDEBUG) then EndOfInstruction(); Hint_WFE(localtimeout, WFxType_WFET);

Base Instructions | SIMD&FP Instructions | SVE Instructions | SME Instructions | Index by Encoding | Shared Pseudocode | Proprietary Notice

Internal version only: isa v33.64, AdvSIMD v29.12, pseudocode v2023-06_rel, sve v2023-06_rel ; Build timestamp: 2023-07-04T19:42

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