Pokémon mini Development Documentation

NEG = Negate

Hex	Mnemonic	Cycles
CE A4	NEG A	3
CE A5	NEG B	3
CE A6 ll	NEG [BR:ll]	5
CE A7	NEG [HL]	4

Execute

A       = Register A
B       = Register B
[BR:ll] = Memory: (EP shl 16) or (BR shl 8) or #nn
[HL]    = Memory: (EP shl 16) or HL

; NEG Ds
;
; Ds = Source/Destination

Ds = 0 - Ds

Description

8-bits Destination is negated.

Conditions

• Zero: Set when result is 0
• Carry: Set when result is not 0
• Overflow: Set when result is 0x80
• Negative: Set when bit 7 of the result is 1

Examples

; A = 0x01
NEG A
; A = 0xFF (0 - 0x01 = 0xFF)
; SC = (Zero=0):(Carry=1):(Overflow=0):(Negative=1)

; B = 0x00
NEG B
; B = 0x00 (0 - 0x00 = 0x00)
; SC = (Zero=1):(Carry=0):(Overflow=0):(Negative=0)

; [HL] = 0x80
NEG [HL]
; [HL] = 0x80 (0 - 0x80 = 0x80)
; SC = (Zero=0):(Carry=1):(Overflow=1):(Negative=1)

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