Zilog Z16F2810 User Manual
Page 112
DEC Instruction
UM018809-0611
96
ZNEO
®
CPU Core
User Manual
DEC
Definition
Decrement
Syntax
DEC dst
Operation
dst
dst
–
1
Description
The contents of the destination operand are decremented by one.
Flags
Flags are set based on the memory destination size, or 32 bits for register destinations.
Syntax and Opcodes
7
6
5
4
3
2
1
0
C
Z
S
V
B
CIRQE IRQE
*
*
*
*
*
–
–
–
Legend
C
= Set to 1 if the result generated a borrow; otherwise set to 0.
Z
= Set to 1 if the result is zero; otherwise, set to 0.
S
= Set to 1 if the result msb is 1; otherwise set to 0.
V
= Set to 1 if an arithmetic overflow occurs; otherwise set to 0.
B
= Set to 1 if the initial destination value was 0; otherwise set to 0.
CIRQE
= No change.
IRQE
= No change.
Instruction, Operands
Word 0
Word 1
Word 2
DEC Rd
1
{AA1H, Rd}
01H
DEC addr16
{ADAH, 1x11B}
addr16
DEC addr32
{ADBH, 1x11B}
addr[31:16]
addr[15:0]
DEC (Rd)
{ACH, 1x11B, Rd}
Note: