Intel 80C186XL, 80C188XL Instruction Set Descriptions, Table C-4.Instruction Set Continued, C-28

INSTRUCTION SET DESCRIPTIONS

Table C-4. Instruction Set (Continued)

Name	Description	Operation	Flags
			Affected
LODS	Load String (Byte or Word):	When Source Operand is a Byte:	AF –
	LODS src-string	(AL) ← (src-string)	CF –
			DF –
	Transfers the byte or word string	if
			IF –
		(DF) = 0
	element addressed by SI to register AL
			OF –
		then
	or AX and updates SI to point to the
			PF –
		(SI) ← (SI) + DELTA
	next element in the string. This
			SF –
		else
	instruction is not ordinarily repeated
			TF –
		(SI) ← (SI) – DELTA
	since the accumulator would be
			ZF –
	overwritten by each repetition, and	When Source Operand is a Word:
	only the last element would be	(AX) ← (src-string)
	retained.
		if
	Instruction Operands:	(DF) = 0
	LODS src-string	then
		(SI) ← (SI) + DELTA
	LODS (repeat) src-string
		else
		(SI) ← (SI) – DELTA
LOOP	Loop:	(CX) ← (CX) – 1	AF –
	LOOP disp8	if	CF –
		(CX) ≠ 0	DF –
	Decrements CX by 1 and transfers
		then	IF –
	control to the target location if CX is
		(IP) ← (IP) + disp8 (sign-ext to 16 bits)	OF –
	not 0; otherwise the instruction
			PF –
	following LOOP is executed.
			SF –
	Instruction Operands:
			TF –
	LOOP short-label		ZF –
LOOPE	Loop While Equal:	(CX) ← (CX) – 1	AF –
LOOPZ	Loop While Zero:	if	CF –
	LOOPE disp8	(ZF) = 1 and (CX) ≠ 0	DF –
		then	IF –
	LOOPZ disp8
		(IP)←(IP) + disp8 (sign-ext to 16 bits)	OF –
	Decrements CX by 1 and transfers
			PF –
	control is to the target location if CX is
			SF –
	not 0 and if ZF is set; otherwise the
			TF –
	next sequential instruction is executed.
			ZF –
	Instruction Operands:
	LOOPE short-label
	LOOPZ short-label

NOTE: The three symbols used in the Flags Affected column are defined as follows:

–the contents of the flag remain unchanged after the instruction is executed ¸? the contents of the flag is undefined after the instruction is executed

the flag is updated after the instruction is executed

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