Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS MANUAL VOLUME 1 REV 2.3 Manual page 1689

WBINVD—Write-Back and Invalidate Cache
Opcode
0F 09
Description
Writes back all modified cache lines in the processor's internal cache to main memory,
invalidates (flushes) the internal caches, and issues a special-function bus cycle that
directs external caches to also write back modified data.
After executing this instruction, the processor does not wait for the external caches to
complete their write-back and flushing operations before proceeding with instruction
execution. It is the responsibility of hardware to respond to the cache write-back and
flush signals.
The WBINVD instruction is a privileged instruction. When the processor is running in
protected mode, the CPL of a program or procedure must be 0 to execute this
instruction. This instruction is also a serializing instruction.
In situations where cache coherency with main memory is not a concern, software can
use the INVD instruction.
Operation
IF Itanium System Environment THEN IA-32_Intercept(INST,WBINVD);
WriteBack(InternalCaches);
Flush(InternalCaches);
SignalWriteBack(ExternalCaches);
SignalFlush(ExternalCaches);
Continue (* Continue execution);
Flags Affected
None.
Additional Itanium System Environment Exceptions
IA-32_Intercept
Protected Mode Exceptions
#GP(0)
Real Address Mode Exceptions
None.
Volume 4: Base IA-32 Instruction Reference
Instruction Description
WBINVD Write-back and flush Internal caches; initiate writing-back and
flushing of external caches.
Mandatory Instruction Intercept.
If the current privilege level is not 0.
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