dsp56800e Freescale Semiconductor, Inc, dsp56800e Datasheet - Page 81

• Manufacturer Part Number: dsp56800e
• Description: 16-bit Digital Signal Controller Core
• Manufacturer: Freescale Semiconductor, Inc

3.6.3.3
The address of the operand is in the address register Rn, N, or SP. After the operand address is used, it is
decremented and stored in the same address register. When a long 32-bit memory location is accessed, the
pointer is decremented by two.
Figure 3-17 demonstrates this addressing mode.
Freescale Semiconductor
Available for: Byte (Byte Pointer), Word, Long
Assembler Syntax: X:(Rn)–, X:(N)–, X:(SP)–
Additional Instruction Execution Cycles: 0
Additional Effective Address Program Words: 0
B
35 32 31
B2
$004735
$004734
Post-Decrement: (Rn)–
0
R2
6
15
23
Before Execution
5
X
X
Figure 3-17. Address Register Indirect: Post-Decrement
B1
X Memory
$004735
4
X
X
Post-Decrement Example:
3
16 15
X
X
X
X
Data Types and Addressing Modes
F
0
0
E
B0
D
C
0
MOVE.W B,X:(R2)-
B
35 32 31
B2
$004735
$004734
0
R2
6
15
23
After Execution
5
6
X
B1
X Memory
$004734
4
5
X
3
16 15
4
X
3
X
F
0
0
Addressing Modes
E
B0
D
C
0
3-31