Texas Instruments TMS320C3x User Manual page 168

Example 6–15. Indirect Addressing With Postindex Add and Modify
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 added
to the auxiliary register.
Operation:
Assembler Syntax:
Modification Field:
AR n
31 24 23
IR m
x
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:
Assembler Syntax:
Modification Field:
AR n
31 24 23
IR m x
operand address = AR n
AR n = AR n + IR m
*AR n ++ (IR m )
01100 if m = 0
10100 if m = 1
31 24 23
x x
x Index
31
operand address = AR n
AR n = AR n – IR m
*AR n – – (IR m )
if m = 0
01101
if m = 1
10101
31 24 23
x x
x Index
31
Indirect Addressing
Address
0
(+)
Operand
Address
0
(–)
Operand
Addressing Modes
0
0
0
0
6-15