eZ80
®
CPU
User Manual
UM007714-0908 CPU Instruction Set
132
DEC (HL)
Decrement
Operation
(HL) ← (HL)–1
Description:
The (HL) operand is an 8-bit value stored at the memory location specified by the contents
of the multibyte register HL. This 8-bit value is decremented by 1.
Condition Bits Affected
Attributes
S Set if result is negative; reset otherwise.
Z Set if result is 0; reset otherwise.
H Set is borrowed from bit 4; reset otherwise.
P/V Set if operand was 80h before operation; reset otherwise.
N Set.
C Not affected.
Mnemonic Operand ADL Mode Cycle Opcode (hex)
DEC (HL) X 4 35
DEC.S (HL) 1 5 52, 35
DEC.L (HL) 0 5 49, 35