9.142 __wfi intrinsic

This intrinsic inserts a WFI instruction into the instruction stream generated by the compiler.

In some architectures, for example the v6T2 architecture, the WFI instruction executes as a NOP instruction.

Syntax

void __wfi(void)

Errors

The compiler does not recognize the __wfi intrinsic when compiling for a target that does not support the WFI instruction. The compiler generates either a warning or an error in this case, depending on the source language:
  • In C code: Warning: #223-D: function "__wfi" declared implicitly.
  • In C++ code: Error: #20: identifier "__wfi" is undefined.
Related reference
9.132 __sev intrinsic
9.119  __nop intrinsic
9.141 __wfe intrinsic
9.143 __yield intrinsic
Related information
NOP
WFI
Non-ConfidentialPDF file icon PDF versionARM DUI0375F
Copyright © 2007, 2008, 2011, 2012, 2014 ARM. All rights reserved.