dsp56800e Freescale Semiconductor, Inc, dsp56800e Datasheet - Page 85

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

3.6.3.7
This addressing mode contains the 6-bit immediate displacement within the instruction word. This field is
always one extended to form a negative offset from –1 to –64. When a long 32-bit memory location is
accessed, the 6-bit displacement is left shifted 1 bit before the addition.
Figure 3-21 demonstrates this addressing mode.
Freescale Semiconductor
Available for: Word, Long
Assembler Syntax: X:(SP–xx)
Additional Instruction Execution Cycles: 1
Additional Effective Address Program Words: 0
A
35 32 31
A2
Index by 6-Bit Displacement: (SP–xx)
$007020
$007000
F
Figure 3-21. Address Register Indirect: Indexed by 6-Bit Displacement
SP
E
Indexed by 6-Bit Displacement Example:
23
15
Before Execution
D
X
X
A1
X Memory
$007020
C
X
X
B
16 15
X
X
from the Instruction Word
One Extend for (SP–xx)
6-Bit Immediate Value
Data Types and Addressing Modes
X
X
A
0
0
9
A0
+
8
7
0
A
MOVE.W A1,X:(SP-32)
35 32 31
A2
$007020
$007000
F
SP
E
15
23
After Execution
D
X
E
A1
X Memory
$007020
C
X
D
B
16 15
X
C
X
B
A
0
0
Addressing Modes
9
A0
8
7
0
3-35