Nintendo GAME BOY Programming Manual page 106

Game Boy Programming Manual
Examples: When A = 3Ch, B = 2Fh, and (HL) = 40h,
; Z ← 0, H ← 1, N ← 1, CY ← 0
CP B
CP 3Ch ; Z ← 1, H ← 0, N ← 1, CY ← 0
CP (HL) ; Z ← 0, H ← 0, N ← 1, CY ← 1
CY H
INC
Increments the contents of register r by 1.
Example: When A = FFh,
INC A ; A ← 0, Z ← 1, H ← 1, N ← 0
INC (HL)
Increments by 1 the contents of memory specified by register pair HL.
Example: When (HL) = 0x50,
INC (HL) ; (HL) ← 0x51, Z ← 0, H ← 0, N ← 0
DEC
Subtract 1 from the contents of register r by 1.
Example: When L = 01h,
DEC L ; L ← 0, Z ← 1, H ← 0, N ← 1
DEC (HL)
Decrements by 1 the contents of memory specified by register pair HL.
Example: When (HL) = 00h,
DEC (HL) ; (HL) ← FFh, Z ← 0, H ← 1, N ← 1
CP r
CP n
CP (HL)
N Z CYCL
r ← r + 1
r
(HL) ← (HL) + 1
r ← r - 1
r
(HL) ← (HL) - 1
CYCL 7 6 5 4 3
1 10 111
2
11 111 110
n
2 10 111 110
7 6 5 4 3 2 1 0
-- *
CY H
-- *
CY H
-- *
CY H
-- *
106
2 1 0
r
0 * 1 00
N Z CYCL 7 6
0 * 3 00
N Z CYCL 7 6
1 * 1 00
N Z CYCL 7 6
1 * 3 00
r 100
5 4 3 2 1 0
110 100
5 4 3 2 1 0
r 101
5 4 3 2 1 0
110 101