Intel 80286 Opcode Instruction Clocks Description, Mem=3 Move byte register into EA byte, 80+

THE 80286 INSTRUCTION SET

MOV-Move Data

Opcode			Instruction	Clocks	Description
88	/r		MOVeb,'rb	2,mem=3.	Move byte register into EA byte
89	/r		MOVew,rw	2,mem=3	Move word register into EA word
8A	/r		MOV rb,eb	2,mem=5	Move EA byte into byte register
88	/r		MOV rw,ew	2,mem=5	Move EA Word into word register
8C	/0		MOVew,ES	2,mem=3	Move ES into EA word
8C	/1		MOVew,CS	2,mem=3	Move CS into EA word
8C	/2		MOVew,SS	2,mem=3	Move SS into EA word
8C	/3		MOVew,OS	2,mem=3	Move OS into EA word
8E	/0		MOV ES,mw	5,pm=19	Move memory word into ES
8E	/0		MOV ES,rw	2,pm=17	Move word register into ES
8E	/2		MOV SS,mw	5,pm=19	Move memory word. into SS
8E	/2		MOV SS,rw	2,pm";'17	Move word register into SS
8E	/3		MOV OS,mw	5,pm=19	Move memory word into OS
8E	/3		MOV OS,rw	2,pm=17	Move word register into OS ,
AO	dw		MOV AL,xb	5	Move byte variable (offset dw) into AL
A1	dw		MOV AX,xw	5	Move word variable (offset dw) into AX
A2	dw		MOV xb,AL	3	Move AL into byte variable (offset dw)
A3	dw		MOV xW,AX	3	Move AX into word register (offset dw)
80+	rb	db	MOV rb,db	2	Move immediate byte into byte register
88+	rw	dw	MOV rw,dw	2	Move immediate word into word register
C6	/0	db	MOVeb,db	2,mem=3	Move immediate byte into EA byte
C7	/0	dw·	MOVew,dw	2,mem=3	Move Immediate word into EA word

FLAGS MODIFIED

None

FLAGS UNDEFINED

None

OPERATION

The second operand is copied to the first operand.

If the destination operand is a segment register (OS, ES, or SS), then the associated segment register cache is also loaded. The data for the cache is obtained from the descriptor table entry for the selector

given..

A null selector (values 0000-0003) can be loaded into OS and ES registers without causing a protection exception. Any use of a segment register with a null selector to address memory will cause #GP(O) exception. No memory reference will occur.

Any move into SS will inhibit all interrupts until after the execution of the next instruction.

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