Hardware Reference
In-Depth Information
Mnemonic
Description
Operands
Status flags
O
S
Z
C
MOV(B)
Move word, byte
r
←
e, e
←
r, e
←
#
-
-
-
-
XCHG(B)
Exchange word
r
←
e
-
-
-
-
LEA
Load effective address
r
#e
-
-
-
-
←
PUSH
Push onto stack
e, #
-
-
-
-
POP
Pop from stack
e
-
-
-
-
PUSHF
Push flags
-
-
-
-
-
POPF
Pop flags
-
-
-
-
-
XLAT
Translate AL
-
-
-
-
-
ADD(B)
Add word
r
←
e, e
←
r, e
←
#
*
*
*
*
ADC(B)
Add word with carry
r
←
e, e
←
r, e
←
#
*
*
*
*
SUB(B)
Subtract word
r
←
e, e
←
r, e
←
#
*
*
*
*
SBB(B)
Subtract word with borrow
r
←
e, e
←
r, e
←
#
*
*
*
*
IMUL(B)
Multiply signed
e
*
U
U
*
MUL(B)
Multiply unsigned
e
*
U
U
*
IDIV(B)
Divide signed
e
U
U
U
U
DIV(B)
Divide unsigned
e
U
U
U
U
CBW
Sign extend byte-word
-
-
-
-
-
CWD
Sign extend word-double
-
-
-
-
NEG(B)
Negate binary
e
*
*
*
*
NOT(B)
Logical complement
e
-
-
-
-
INC(B)
Increment destination
e
*
*
*
-
DEC(B)
Decrement destination
e
*
*
*
-
AND(B)
Logical and
e
r, r
e, e
#
0
*
*
0
←
←
←
OR(B)
Logical or
e
←
r, r
←
e, e
←
#
0
*
*
0
XOR(B)
Logical exclusive or
e
←
r, r
←
e, e
←
#
0
*
*
0
SHR(B)
Logical shift right
e
←
1, e
←
CL
*
*
*
*
SAR(B)
Arithmetic shift right
e
←
1, e
←
CL
*
*
*
*
SAL(B) (=SHL(B))
shift left
e
1, e
CL
*
*
*
*
←
←
ROL(B)
Rotate left
e
←
1, e
←
CL
*
-
-
*
ROR(B)
Rotate right
e
←
1, e
←
CL
*
-
-
*
RCL(B)
Rotate left with carry
e
←
1, e
←
CL
*
-
-
*
RCR(B)
Rotate right with carry
e
←
1, e
←
CL
*
-
-
*
TEST(B)
Test operands
e
r, e
#
0
*
*
0
←
←
CMP(B)
Compare operands
e
←
r, e
←
#
*
*
*
*
STD
Set direction flag (
↓
)
-
-
-
-
-
CLD
Clear direction flag (
↑
)
-
-
-
-
-
STC
Set carry flag
-
-
-
-
1
CLC
Clear carry flag
-
-
-
-
0
CMC
Complement carry
-
-
-
-
*
LOOP
Jump back if decremented CX
≥
0
label
-
-
-
-
LOOPZ LOOPE
Back if Z=1 and DEC(CX)
≥
0
label
-
-
-
-
LOOPNZ LOOPNE
Back if Z=0 and DEC(CX)
≥
0
label
-
-
-
-
REP REPZ REPNZ
Repeat string instruction
string instruction
-
-
-
-
MOVS(B)
Move word string
-
-
-
-
-
LODS(B)
Load word string
-
-
-
-
-
STOS(B)
Store word string
-
-
-
-
-
SCAS(B)
Scan word string
-
*
*
*
*
CMPS(B)
Compare word string
-
*
*
*
*
JCC
Jump according conditions
label
-
-
-
-
JMP
Jump to label
e,
label
-
-
-
-
CALL
Jump to subroutine
e,
label
-
-
-
-
RET
Return from subroutine
-, #
-
-
-
-
SYS
System call trap
-
-
-
-
-
Figure C-4.
Some of the most important 8088 instructions.
