Dec (Decrement) - Hitachi H8/300L Series Programming Manual

2.2.25 DEC (decrement)

Operation
Rd - 1 → Rd
Assembly-Language Format
DEC Rd
Operand Size
Byte
Condition Code
I H
— — — —
I: Previous value remains unchanged.
H: Previous value remains unchanged.
N: Set to 1 when the result is negative; otherwise cleared to 0.
Z: Set to I when the result is zero; otherwise cleared to 0.
V: Set to 1 when an overflow occurs (the previous value in Rd was H'80); otherwise cleared
to 0.
C: Previous value remains unchanged.
Description
This instruction decrements an 8-bit general register and places the result in the general register.
Instruction Formats and Number of Execution States
Addressing
mode Mnem.
Register direct DEC
N Z V C
∆ ∆ ∆
—
Instruction code
Operands 1st byte
Rd 1 A
2nd byte 3rd byte
0 rd
No. of
4th byte states
2
79