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)

N/A

N/A

N/A

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