Nintendo GAME BOY Programming Manual page 115

SET b,
Sets to 1 the specified bit in specified register r.
Example: When A = 80h and L = 3Bh,
SET 3, A ; A ← 0x84
SET 7, L ; L ← 0xBB
SET
Sets to 1 the specified bit in the memory contents specified by registers H and L.
Example: When 00h is the memory contents specified by H and L,
SET 3, (HL) ; (HL) ← 04H
RES
Resets to 0 the specified bit in the specified register r.
Example: When A = 80h and L = 3Bh,
RES 7, A ; A ← 00h
RES 1, L ; L ← 39h
RES b,
Resets to 0 the specified bit in the memory contents specified by registers H and L.
Example: When 0xFF is the memory contents specified by H and L,
RES 3, (HL) ; (HL) ← F7h
← 1
r r
b
← 1
b, (HL) (HL)
b
← 0
b, r r
b
← 0
(HL) (HL)
b
CY H
-- -- --
CY H
-- -- --
CY H
-- -- --
CY H N
-- -- --
115
Chapter 4: CPU Instruction Set
N Z CYCL 7 6 5 4 3
-- 2 11
11
N Z CYCL 7 6 5 4 3
-- 4 11 001
11
N Z CYCL 7 6 5 4 3
-- 2 11 001
10
Z CYCL 7 6 5 4 3
-- 4 11 001
10
2 1 0
001 011
b r
2 1 0
011
b 110
2 1 0
011
b r
2 1 0
011
b 110