SUB - Revision history

Mike: fixing a typo,

2009-08-09T17:22:49Z

fixing a typo,

← Older revision		Revision as of 17:22, 9 August 2009
Line 11:		Line 11:

	== Flags affected ==		== Flags affected ==
	The [[carry indicator]] ('''C''') is set to 1 if a [[Wikipedia:Carry (arithmetic)\|carry occurs]] from the sign bit positions of the adder, otherwise the carry indicator is reset to 0. If the signs of the two operands are equal, but the sign of the result is different, overflow has occurred, and both the [[dynamic overflow indicator]] ('''O''') and the [[static overflow indicator]] ('''Q''') are set to one. If the condition for overflow does not exist, the dynamic overflow indicator is reset to 0, while the static overflow indicator is left unchanged.		The [[carry indicator]] ('''C''') is set to 1 if a [[Wikipedia:Carry (arithmetic)\|carry occurs]] from the sign bit positions of the adder, otherwise the carry indicator is reset to 0. If the signs of the two operands are equal, but the sign of the result is different, overflow has occurred, and both the [[dynamic overflow indicator]] ('''Q''') and the [[static overflow indicator]] ('''O''') are set to one. If the condition for overflow does not exist, the dynamic overflow indicator is reset to 0, while the static overflow indicator is left unchanged.

TArntsen: Spellfix: Arcitecture -> Architecture

2009-08-03T13:33:01Z

Spellfix: Arcitecture -> Architecture

← Older revision		Revision as of 13:33, 3 August 2009
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	\|Code=060 000		\|Code=060 000
	\|Affected=A:=A-(ea), C, O, Q		\|Affected=A:=A-(ea), C, O, Q
	\|~~Arcitecture~~=[[ND-100]], [[ND-110 CPU\|ND-110]]		\|Architecture=[[ND-100]], [[ND-110 CPU\|ND-110]]
	}}		}}

TArntsen: SUB instruction

2009-07-29T09:52:21Z

SUB instruction

New page

{{InstructionBox
|Mnemonic=SUB
|Description=Subtract from A register
|Format=SUB ''<[[ND-100 addressing modes|addr. mode]]> <[[displacement|disp.]]>''
|Code=060 000
|Affected=A:=A-(ea), C, O, Q
|Arcitecture=[[ND-100]], [[ND-110 CPU|ND-110]]
}}

'''SUB''' is an assembly instruction. It subtracts the contents of the memory location pointed to by the [[effective address]] from the [[A register]], leaving the result in the A register. The instruction is performed by forming the 2's complement of the 16-bit word in the effective address and add it to the content of the A register, so flags (see below) are affected exactly the same was as for the [[ADD]] instruction.

== Flags affected ==
The [[carry indicator]] ('''C''') is set to 1 if a [[Wikipedia:Carry (arithmetic)|carry occurs]] from the sign bit positions of the adder, otherwise the carry indicator is reset to 0. If the signs of the two operands are equal, but the sign of the result is different, overflow has occurred, and both the [[dynamic overflow indicator]] ('''O''') and the [[static overflow indicator]] ('''Q''') are set to one. If the condition for overflow does not exist, the dynamic overflow indicator is reset to 0, while the static overflow indicator is left unchanged.

== References ==
*{{ND-doc|06.014.02|Page 135 (3-21)}}
*{{ND-doc|06.029.01|Page 66}}

[[Category:ND-100 instructions]]