Texas Instruments TMS320C3x - Manual (Page 481)

Group Addressing Mode Instruction Encoding
13-23 Assembly Language Instructions
Table 13–10. Indirect Addressing (Continued)
(c) Indirect addressing with index register IR1
Mod Field Syntax Operation Description
10000 *+ AR n(IR1) addr = AR n + IR1 With preindex (IR1) add
10001 * – AR n(IR1) addr = AR n – IR1 With preindex (IR1) subtract
10010 * ++ AR n(IR1) addr = AR n + IR1
AR n = ARn + IR1
With preindex (IR1) add and modify
10011 * – – AR n(IR1) addr = AR n – IR1
AR n = ARn – IR1
With preindex (IR1) subtract and modify
10100 * AR n ++ (IR1) addr = AR n
AR n = ARn + IR1
With postindex (IR1) add and modify
10101 *AR n – – (IR1) addr = AR n
AR n = ARn – IR1
With postindex (IR1) subtract and modify
10110 * AR n ++ (IR1)% addr = AR n
AR n = circ(ARn + IR1)
With postindex (IR1) add and circular modify
10111 * AR n – – (IR1)% addr = AR n
AR n = circ(ARn – IR1)
With postindex (IR1) subtract and circular modify
(d) Indirect addressing (special cases)
Mod Field Syntax Operation Description
11000 *AR n addr = AR n Indirect
11001 *AR n ++ (IR0)B addr = AR n
AR n = B(ARn + IR0)
With postindex (IR0) add
and bit-reversed modify
Legend: addr memory address circ( ) address in circular addressing
AR n auxiliary registers AR0–AR7 ++ add and modify by one
B where bit-reversed addressing is performed % where circular addressing is performed
B() bit-reversed address IR n index register IR0 or IR1
– – subtract and modify by one