AMD Confidential
User Manual November 21st, 2008
Appendix A 221
Instruction
Supported
Mnemonic
Opcode
Description
IRETD
CF
Return from interrupt (32-bit operand size).
1
IRETQ
CF
Return from interrupt (64-bit operand size).
1
LAR reg16,reg/mem16
0F 02 /r
Reads the GDT/LDT descriptor referenced by
the 16-bit source operand masks the
attributes with FF00h and saves the result
in the 16-bit destination register.

LAR reg32,reg/mem16
0F 02 /r
Reads the GDT/LDT descriptor referenced by
the 16-bit source operand masks the
attributes with 00FFFF00h and saves the
result in the 32-bit destination register.

LAR reg64,reg/mem16
0F 02 /r
Reads the GDT/LDT descriptor referenced by
the 16-bit source operand, masks the
attributes with 00FFFF00h and saves the
result in the 64-bit destination register.

LGDT mem16:32
0F 01 /2
Loads mem16:32 into the global descriptor
table register.

LGDT mem16:64
0F 01 /2
Loads mem16:64 into the global descriptor
table register.

LIDT mem16:32
0F 01 /3
Loads mem16:32 into the interrupt descriptor
table register.

LIDT mem16:64
0F 01 /3
Loads mem16:64 into the interrupt descriptor
table register.

LLDT reg/mem16
0F 00 /2
Load the 16-bit segment selector into the
local descriptor table register and load the
LDT descriptor from the GDT.

LMSW reg/mem16
0F 01 /6
Loads the lower 4 bits of the source into
the lower 4 bits of CR0.

LSL reg16,reg/mem16
0F 03 /r
Loads a 16-bit general-purpose register with
the segment limit or a selector specified in
a 16-bit memory or register operand.

LSL reg32,reg/mem16
0F 03 /r
Loads a 32-bit general-purpose register with
the segment limit or a selector specified in
a 16-bit memory or register operand.

LSL reg64,reg/mem16
0F 03 /r
Loads a 64-bit general-purpose register with
the segment limit or a selector specified in
a 16-bit memory or register operand.

LTR reg/mem16
0F 00 /3
Load the 16-bit segment selector into the
task register and load the TSS descriptor
from the GDT.

MOV CRn,reg32
0F 22 /r
Move the contents of a 32-bit register to
CRn.

MOV CRn,reg64
0F 22 /r
Move the contents of a 64-bit register to
CRn.

MOV reg32,CRn
0F 20 /r
Move the contents of CRn to a 32-bit
register.

MOV reg64,CRn
0F 20 /r
Move the contents of CRn to a 64-bit
register.

MOV DRn,reg32
0F 21 /r
Move the contents of a 32-bit register to
DRn.

MOV DRn,reg64
0F 21 /r
Move the contents of a 64-bit register to
DRn.

MOV reg32,DRn
0F 23 /r
Move the contents of DRn to a 32-bit
register.

MOV reg64,DRn
0F 23 /r
Move the contents of DRn to a 64-bit
register.

RDMSR
0F 32
Copy MSR specified by ECX into EDX:EAX.

RDPMC
0F 33
Copy the performance monitor counter
specified by ECX into EDX:EAX.

RDTSC
0F 31
Copy the time-stamp counter into EDX:EAX.

RSM
0F AA
Resume operation of an interrupted program.

1 See Section A.6.3.2, “IRET Return from Interrupt”, on page 225.