System instructions, Table 15-8: general-purpose instruction reference, A.6.3 system instructions – AMD SimNow Simulator 4.4.5 User Manual
Page 232: Amd confidential user manual november 21
AMD Confidential
User Manual
November 21
st
, 2008
220
Appendix A
Instruction
Supported
Mnemonic
Opcode
Description
XOR reg/mem64,reg64
31 /r
XOR
the
contents
of
a
64-bit
destination
register
or
memory
operand with the contents of a 64-bit
register and store the result in the
destination.
XOR reg8,reg/mem8
32 /r
XOR
the
contents
of
an
8-bit
destination
register
with
the
contents of an 8-bit register or
memory operand and store the result
in the destination.
XOR reg16,reg/mem16
33 /r
XOR
the
contents
of
a
16-bit
destination
register
with
the
contents of a 16-bit register or
memory operand and store the result
in the destination.
XOR reg32,reg/mem32
33 /r
XOR
the
contents
of
a
32-bit
destination
register
with
the
contents of a 32-bit register or
memory operand and store the result
in the destination.
XOR reg64,reg/mem64
33 /r
XOR
the
contents
of
a
64-bit
destination
register
with
the
contents of a 64-bit register or
memory operand and store the result
in the destination.
Table 15-8: General-Purpose Instruction Reference
A.6.3 System Instructions
This chapter describes the function, mnemonic syntax and opcodes that the simulator
simulates. The system instructions are used to establish the operating mode, access
processor resources, handle program and system errors, and manage memory. Many of
these instructions can only be executed by privileged software, such as the operating
system kernel and interrupt handlers, that run at the highest privilege level. Only system
instructions can access certain processor resources, such as the control registers, model-
specific register, and debug registers.
Instruction
Supported
Mnemonic
Opcode
Description
ARPL reg/mem16,reg16
63 /r
Adjust the RPL of a destination segment
selector to a level not less than the RPL of
the segment selector specifies in the 16-bit
source register.
1
CLI
FA
Clear the interrupt flag (IF) to zero.
CLTS
0F 06
Clear the task-switched (TS) flag in CR0 to
0.
HLT
F4
Halt instruction execution.
INT 3
CC
Trap to debugger at interrupt 3.
2
INVD
0F 08
Flush internal caches and trigger external
cache flushes.
INVLPG mem8
0F 01 /7
Invalidate the TLB entry for the page
containing a specified memory location.
IRET
CF
Return from interrupt (16-bit operand size).
1
In 64-bit mode, this opcode (0x63) is used for the MOVSXD instruction.
2
See Section A.6.3.1, “INT – Interrupt to Vector”, on page 225.