dsp56800e Freescale Semiconductor, Inc, dsp56800e Datasheet - Page 84

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

Data Types and Addressing Modes
3.6.3.6
This addressing mode contains the 3-bit immediate displacement within the instruction word. This field is
always one extended to form a negative offset from –1 to –8 when the SP register is used. The field is
always zero extended to form a positive offset from 0 to 7 when R0, R1, R2, R3, R4, R5, or the N register
is used.
Figure 3-20 demonstrates this addressing mode.
3-34
Available for: Byte (Word Pointer), Word
Assembler Syntax: X:(Rn+x), X:(N+x), X:(SP–x)
Additional Instruction Execution Cycles: 1
Additional Effective Address Program Words: 0
A
35 32 31
A2
Index by 3-Bit Displacement: (RRR+x), (SP–x)
$007003
$007000
F
Figure 3-20. Address Register Indirect: Indexed by 3-Bit Displacement
R4
E
Indexed by 3-Bit Displacement Example:
15
23
Before Execution
D
X
X
A1
X Memory
$007000
C
X
X
B
16 15
X
X
from the Instruction Word
Zero Extend for (RRR+x)
One Extend for (SP–x)
3-Bit Immediate Value
DSP56800E Core Reference Manual
X
X
A
0
0
9
A0
+
8
7
0
A
MOVE.W A1,X:(R4+3)
35 32 31
A2
$007003
$007000
F
R4
E
15
23
After Execution
D
E
X
A1
X Memory
$007000
C
D
X
B
16 15
C
X
Freescale Semiconductor
B
X
A
0
0
9
A0
8
7
0