Intel 80C188XL, 80C186XL user manual Sbb, Subtract With Borrow, SBB dest, src

		INSTRUCTION SET DESCRIPTIONS
	Table C-4. Instruction Set (Continued)
Name	Description	Operation	Flags
			Affected
SBB	Subtract With Borrow:	if	AF
	SBB dest, src	(CF) = 1	CF
		then	DF –
	Subtracts the source from the desti-
		(dest) = (dest) – (src) – 1	IF –
	nation, subtracts one if CF is set, and
		else	OF
	returns the result to the destination
		(dest) ← (dest) – (src)	PF
	operand. Both operands may be bytes
			SF
	or words. Both operands may be
			TF –
	signed or unsigned binary numbers
			ZF ¸
	(see AAS and DAS)
	Instruction Operands:
	SBB reg, reg
	SBB reg, mem
	SBB mem, reg
	SBB accum, immed
	SBB reg, immed
	SBB mem, immed

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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