eZ80
®
CPU
User Manual
UM007714-0908 CPU Instruction Set
139
DEC SP
Decrement
Operation
SP ← SP – 1
Description
The value contained in the Stack Pointer (
SP
) register is decremented by 1. In ADL mode,
or when the
.L
suffix is employed, SPL is used for
SP
. In Z80 mode, or when the
.S
suffix
is employed, the SPS is used for
SP
.
Condition Bits Affected
None.
Attributes
Mnemonic Operand ADL Mode Cycle Opcode (hex)
DEC SP X13B
DEC.S SP 1252, 3B
DEC.L SP 0249, 3B