RDPID—Read Processor ID

Opcode/Instruction Op/En 64/32-bit Mode CPUID Feature Flag Description
F3 0F C7 /7 RDPID r32 R N.E./V RDPID Read IA32_TSC_AUX into r32.
F3 0F C7 /7 RDPID r64 R V/N.E. RDPID Read IA32_TSC_AUX into r64.

Instruction Operand Encoding1

Op/En Operand 1 Operand 2 Operand 3 Operand 4
R ModRM:r/m (w) NA NA NA

Description

Reads the value of the IA32_TSC_AUX MSR (address C0000103H) into the destination register. The value of CS.D and operand-size prefixes (66H and REX.W) do not affect the behavior of the RDPID instruction.

Operation

DEST := IA32_TSC_AUX

Flags Affected

None.

Protected Mode Exceptions

#UD

If the LOCK prefix is used.

If CPUID.7H.0:ECX.RDPID[bit 22] = 0.

Real-Address Mode Exceptions

Same exceptions as in protected mode.

Virtual-8086 Mode Exceptions

Same exceptions as in protected mode.

Compatibility Mode Exceptions

Same exceptions as in protected mode.

64-Bit Mode Exceptions

Same exceptions as in protected mode.

1.ModRM.MOD = 011B required