Intel 80286 Computer Accessories User Manual


 
THE
80286
INSTRUCTION SET
X
CHG
- Exchange Memory/Register with Register
Opcode
Instruction Clocks Description
86
Ir
XCHG
eb,rb
3,mem=5
Exchange byte register with
EA
byte
86
Ir
XCHG
rb,eb
3,mem=5
Exchange
EA
byte with byte register
87
Ir
XCHG
eW,rw
3,mem=5
Exchange word register with
EA
word
87
Ir
XCHG
rW,ew
3,mem=5
Exchange
EA
word with word register
90+
rw
XCHG
AX,rw 3
Exchange word register with
AX
90+
rw
XCHG
rW,AX
3
Exchange with word register
FLAGS MODIFIED
None
FLAGS UNDEFINED
None
OPERATION
The
two operands are exchanged.
The
order
of
the operands
is
immaterial. BUS
LOCK
is
asserted for
the duration
of
the exchange, regardless
of
the presence or absence of the
LOCK
prefix or IOPL.
PROTECTED MODE EXCEPTIONS
#GP(O)
if
either operand
is
in a non-writable segment. #GP(O) for an illegal memory operand effective
address in the
CS,
DS, or
ES
segments; #SS(O) for an illegal address
in
the
SS
segment.
REAL ADDRESS MODE EXCEPTIONS
Interrupt
13
for a word operand
at
offset OFFFFH.
8-114