PM Opc OR

OR = Logical Inclusive-OR

Hex	Mnemonic	Cycles
28	OR A, A	8
29	OR A, B	8
2A nn	OR A, #nn	8
2B	OR A, [HL]	8
2C nn	OR A, [N+#nn]	12
2D nn nn	OR A, [#nnnn]	16
2E	OR A, [X]	8
2F	OR A, [Y]	8
9D nn	OR F, #nn	12
CE B4 nn	OR B, #nn	12
CE B5 nn	OR L, #nn	12
CE B6 nn	OR H, #nn	12
D9 nn nn	OR [N+#nn], #nn	20
CE 28 ss	OR A, [X+#ss]	16
CE 29 ss	OR A, [Y+#ss]	16
CE 2A	OR A, [X+L]	16
CE 2B	OR A, [Y+L]	16
CE 2C	OR [HL], A	16
CE 2D nn	OR [HL], #nn	20
CE 2E	OR [HL], [X]	20
CE 2F	OR [HL], [Y]	20

Execute

#nn     = Immediate unsigned 8-Bits
A       = Register A
B       = Register B
L       = Register L
H       = Register H
F       = Register F
[N+#nn] = Memory: (I shl 16) or (N shl 8) or #nn
[HL]    = Memory: (I shl 16) or HL
[X]     = Memory: (XI shl 16) or X
[Y]     = Memory: (YI shl 16) or Y
[#nnnn] = Memory: #nnnn
[X+#ss] = Memory: (XI shl 16) or (X + #ss)
[Y+#ss] = Memory: (YI shl 16) or (Y + #ss)
[X+L]   = Memory: (XI shl 16) or (X + signed(L))
[Y+L]   = Memory: (YI shl 16) or (Y + signed(L))

; OR Ds, Sc
;
; Ds = Destination
; Sc = Source

Ds = Ds OR Sc

Description

"8-Bits Destination" Logic OR (Inclusive-OR) with "8-Bits Source".

Can be used to set one or multiple bits.

Bit 0 - Mask $01
Bit 1 - Mask $02
Bit 2 - Mask $04
Bit 3 - Mask $08
Bit 4 - Mask $10
Bit 5 - Mask $20
Bit 6 - Mask $40
Bit 7 - Mask $80
All   - Mask $FF

Conditions

Zero: Set when result is 0

Sign: Set when bit 7 of the result is 1

Carry and Overflow remain unchanged

Examples

; A = 0x45
OR A, $40
; A = 0x45
; F = (Zero=0):(Sign=0)

; B = 0xF0
OR B, $04
; B = 0xF4
; F = (Zero=0):(Sign=1)

; A = 0xF0
OR A, $55
; A = 0xF5
; F = (Zero=0):(Sign=1)

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