📄 +Ҧ
字号:
reg32,mem32 - - 16 11 3-7
LDS - Load Pointer Using DS
Usage: LDS dest,src
Modifies flags: None
Loads 32-bit pointer from memory source to destination register
and DS. The offset is placed in the destination register and the
segment is placed in DS. To use this instruction the word at the
lower memory address must contain the offset and the word at the
higher address must contain the segment. This simplifies the loading
of far pointers from the stack and the interrupt vector table.
Clocks Size
Operands 808x 286 386 486 Bytes
reg16,mem32 16+EA 7 7 6 2-4
reg,mem (PM) - - 22 12 5-7
LEA - Load Effective Address
Usage: LEA dest,src
Modifies flags: None
Transfers offset address of "src" to the destination register.
Clocks Size
Operands 808x 286 386 486 Bytes
reg,mem 2+EA 3 2 1 2-4
- the MOV instruction can often save clock cycles when used in
place of LEA on 8088 processors
LEAVE - Restore Stack for Procedure Exit (80188+)
Usage: LEAVE
Modifies flags: None
Releases the local variables created by the previous ENTER
instruction by restoring SP and BP to their condition before
the procedure stack frame was initialized.
Clocks Size
Operands 808x 286 386 486 Bytes
none - 5 4 5 1
LES - Load Pointer Using ES
Usage: LES dest,src
Modifies flags: None
Loads 32-bit pointer from memory source to destination register
and ES. The offset is placed in the destination register and the
segment is placed in ES. To use this instruction the word at the
lower memory address must contain the offset and the word at the
higher address must contain the segment. This simplifies the loading
of far pointers from the stack and the interrupt vector table.
Clocks Size
Operands 808x 286 386 486 Bytes
reg,mem 16+EA 7 7 6 2-4 (W88=24+EA)
reg,mem (PM) - - 22 12 5-7
LFS - Load Pointer Using FS (386+)
Usage: LFS dest,src
Modifies flags: None
Loads 32-bit pointer from memory source to destination register
and FS. The offset is placed in the destination register and the
segment is placed in FS. To use this instruction the word at the
lower memory address must contain the offset and the word at the
higher address must contain the segment. This simplifies the loading
of far pointers from the stack and the interrupt vector table.
Clocks Size
Operands 808x 286 386 486 Bytes
reg,mem - - 7 6 5-7
reg,mem (PM) - - 22 12 5-7
LGDT - Load Global Descriptor Table (286+ privileged)
Usage: LGDT src
Modifies flags: None
Loads a value from an operand into the Global Descriptor Table
(GDT) register.
Clocks Size
Operands 808x 286 386 486 Bytes
mem64 - 11 11 11 5
LIDT - Load Interrupt Descriptor Table (286+ privileged)
Usage: LIDT src
Modifies flags: None
Loads a value from an operand into the Interrupt Descriptor Table
(IDT) register.
Clocks Size
Operands 808x 286 386 486 Bytes
mem64 - 12 11 11 5
LGS - Load Pointer Using GS (386+)
Usage: LGS dest,src
Modifies flags: None
Loads 32-bit pointer from memory source to destination register
and GS. The offset is placed in the destination register and the
segment is placed in GS. To use this instruction the word at the
lower memory address must contain the offset and the word at the
higher address must contain the segment. This simplifies the loading
of far pointers from the stack and the interrupt vector table.
Clocks Size
Operands 808x 286 386 486 Bytes
reg,mem - - 7 6 5-7
reg,mem (PM) - - 22 12 5-7
LLDT - Load Local Descriptor Table (286+ privileged)
Usage: LLDT src
Modifies flags: None
Loads a value from an operand into the Local Descriptor Table
Register (LDTR).
Clocks Size
Operands 808x 286 386 486 Bytes
reg16 - 17 20 11 3
mem16 - 19 24 11 5
LMSW - Load Machine Status Word (286+ privileged)
Usage: LMSW src
Modifies flags: None
Loads the Machine Status Word (MSW) from data found at "src"
Clocks Size
Operands 808x 286 386 486 Bytes
reg16 - 3 10 13 3
mem16 - 6 13 13 5
LOCK - Lock Bus
Usage: LOCK
LOCK: (386+ prefix)
Modifies flags: None
This instruction is a prefix that causes the CPU assert bus lock
signal during the execution of the next instruction. Used to
avoid two processors from updating the same data location. The
286 always asserts lock during an XCHG with memory operands. This
should only be used to lock the bus prior to XCHG, MOV, IN and
OUT instructions.
Clocks Size
Operands 808x 286 386 486 Bytes
none 2 0 0 1 1
LODS - Load String (Byte, Word or Double)
Usage: LODS src
LODSB
LODSW
LODSD (386+)
Modifies flags: None
Transfers string element addressed by DS:SI (even if an operand is
supplied) to the accumulator. SI is incremented based on the size
of the operand or based on the instruction used. If the Direction
Flag is set SI is decremented, if the Direction Flag is clear SI
is incremented. Use with REP prefixes.
Clocks Size
Operands 808x 286 386 486 Bytes
src 12/16 5 5 5 1
LOOP - Decrement CX and Loop if CX Not Zero
Usage: LOOP label
Modifies flags: None
Decrements CX by 1 and transfers control to "label" if CX is not
Zero. The "label" operand must be within -128 or 127 bytes of the
instruction following the loop instruction
Clocks Size
Operands 808x 286 386 486 Bytes
label: jump 18 8+m 11+m 6 2
no jump 5 4 ? 2
LOOPE/LOOPZ - Loop While Equal / Loop While Zero
Usage: LOOPE label
LOOPZ label
Modifies flags: None
Decrements CX by 1 (without modifying the flags) and transfers
control to "label" if CX != 0 and the Zero Flag is set. The
"label" operand must be within -128 or 127 bytes of the instruction
following the loop instruction.
Clocks Size
Operands 808x 286 386 486 Bytes
label: jump 18 8+m 11+m 9 2
no jump 5 4 ? 6
LOOPNZ/LOOPNE - Loop While Not Zero / Loop While Not Equal
Usage: LOOPNZ label
LOOPNE label
Modifies flags: None
Decrements CX by 1 (without modifying the flags) and transfers
control to "label" if CX != 0 and the Zero Flag is clear. The
"label" operand must be within -128 or 127 bytes of the instruction
following the loop instruction.
Clocks Size
Operands 808x 286 386 486 Bytes
label: jump 19 8+m 11+m 9 2
no jump 5 4 ? 6
LSL - Load Segment Limit (286+ protected)
Usage: LSL dest,src
Modifies flags: ZF
Loads the segment limit of a selector into the destination register
if the selector is valid and visible at the current privilege level.
If loading is successful the Zero Flag is set, otherwise it is
cleared.
Clocks Size
Operands 808x 286 386 486 Bytes
reg16,reg16 - 14 20/25 10 3
reg32,reg32 - - 20/25 10 3
reg16,mem16 - 16 21/26 10 5
reg32,mem32 - - 21/26 10 5
- 386 times are listed "byte granular" / "page granular"
LSS - Load Pointer Using SS (386+)
Usage: LSS dest,src
Modifies flags: None
Loads 32-bit pointer from memory source to destination register
and SS. The offset is placed in the destination register and the
segment is placed in SS. To use this instruction the word at the
lower memory address must contain the offset and the word at the
higher address must contain the segment. This simplifies the loading
of far pointers from the stack and the interrupt vector table.
Clocks Size
Operands 808x 286 386 486 Bytes
reg,mem - - 7 6 5-7
reg,mem (PM) - - 22 12 5-7
LTR - Load Task Register (286+ privileged)
Usage: LTR src
Modifies flags: None
Loads the current task register with the value specified in "src".
Clocks Size
Operands 808x 286 386 486 Bytes
reg16 - 17 23 20 3
mem16 - 19 27 20 5
MOV - Move Byte or Word
Usage: MOV dest,src
Modifies flags: None
Copies byte or word from the source operand to the destination
operand. If the destination is SS interrupts are disabled except
on early buggy 808x CPUs. Some CPUs disable interrupts if the
destination is any of the segment registers
Clocks Size
Operands 808x 286 386 486 Bytes
reg,reg 2 2 2 1 2
mem,reg 9+EA 3 2 1 2-4 (W88=13+EA)
reg,mem 8+EA 5 4 1 2-4 (W88=12+EA)
mem,immed 10+EA 3 2 1 3-6 (W88=14+EA)
reg,immed 4 2 2 1 2-3
mem,accum 10 3 2 1 3 (W88=14)
accum,mem 10 5 4 1 3 (W88=14)
segreg,reg16 2 2 2 3 2
segreg,mem16 8+EA 5 5 9 2-4 (W88=12+EA)
reg16,segreg 2 2 2 ⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -