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
1.ModRM.MOD = 011B required
| 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.
This UNOFFICIAL, mechanically-separated, non-verified reference is provided for convenience, but it may be incomplete or broken in various obvious or non-obvious ways. Refer to Intel® 64 and IA-32 Architectures Software Developer’s Manual for anything serious.