Intel 80C186XL, 80C188XL user manual Decrement

INSTRUCTION SET DESCRIPTIONS

Table C-4. Instruction Set (Continued)

Name	Description	Operation	Flags
			Affected
DEC	Decrement:	(dest) ← (dest) – 1	AF
	DEC dest		CF –
			DF –
	Subtracts one from the destination
			IF –
	operand. The operand may be a byte
			OF
	or a word and is treated as an
			PF
	unsigned binary number (see AAA and
			SF
	DAA).
			TF –
	Instruction Operands:
			ZF ¸
	DEC reg
	DEC mem

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

C-12