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)