Texas Instruments TMS320C3x - Manual (Page 168)

Indirect Addressing
6-15 Addressing Modes
Example 6–15. Indirect Addressing With Postindex Add and Modify
The address of the operand to fetch is the contents of an auxiliary register
(AR
n). After the operand is fetched, the index register (IR0 or IR1) is added
to the auxiliary register.
Operation: operand address = AR n
AR n = ARn + IRm
Assembler Syntax: *AR n ++ (IRm)
Modification Field: 01100 if m = 0
10100 if m = 1
Index
(+)
0
0 31 24 23
Address x x AR n
31
x x
0
31
24 23
Operand
IR m
Example 6–16. Indirect Addressing With Postindex Subtract and Modify
The address of the operand to fetch is the contents of an auxiliary register (AR n).
After the operand is fetched, the index register (IR0 or IR1) is subtracted from
the auxiliary register.
Operation: operand address = AR n
AR n = ARn – IRm
Assembler Syntax: *AR n – – (IRm)
Modification Field: 01101 if m = 0
10101 if m = 1
(–)
0
0 31 24 23
Address x x AR n
31
IR m x x
0
31
24 23
Index
Operand