Texas Instruments C28 Series Student Guide

Indirect Addressing
Indirect Addressing
Indirect Addressing
Indirect Addressing
–
–
“
“
*
*
”
”


Auxiliary Registers (
Auxiliary Registers (
XARn
XARn
) used to access full
) used to access full
data memory space
data memory space


Address Register Arithmetic Unit (ARAU) used
Address Register Arithmetic Unit (ARAU) used
to modify the
to modify the
XARn
XARn


Access data from arrays anywhere in data
Access data from arrays anywhere in data
memory in an orderly fashion
memory in an orderly fashion
Data Memory
Data Memory
XAR0
XAR0
XAR1
XAR1
XAR2
XAR2
XAR3
XAR3
XAR4
XAR4
XAR5
XAR5
XAR6
XAR6
XAR7
XAR7
ARAU
ARAU
Any of eight hardware pointers (ARs) may be employed to access values from the first 64K of
data memory. Auto-increment or decrement is supported at no additional cycle cost. XAR register
formats offer larger 32-bit widths, allowing them to access across the full 4-Giga words data
space.
Indirect Addressing Modes
Indirect Addressing Modes


Auto
Auto
-
-
increment / decrement: *
increment / decrement: *
XARn
XARn
++, *
++, *
--
--
XARn
XARn


Post
Post
-
-
increment or Pre
increment or Pre
-
-
decrement
decrement


Offset: *+
Offset: *+
XARn
XARn
[AR0 or AR1], *+
[AR0 or AR1], *+
XARn
XARn
[3bit]
[3bit]


Offset by 16
Offset by 16
-
-
bit AR0 or AR1, or 3
bit AR0 or AR1, or 3
-
-
bit constant
bit constant


Stack Relative: *
Stack Relative: *
-
-
SP[6bit]
SP[6bit]


Index by 6
Index by 6
-
-
bit offset (optimal for C)
bit offset (optimal for C)


Immediate Direct: *(0:16bit)
Immediate Direct: *(0:16bit)


Access low 64K
Access low 64K


Circular: *AR6%++
Circular: *AR6%++


AR1(7:0) is buffer size
AR1(7:0) is buffer size


XAR6 is current address
XAR6 is current address
B - 10 C28x - Appendix B - Addressing Modes

Texas Instruments C28 Series Specifications

General

Brand	Texas Instruments
Model	C28 Series
Category	Computer Hardware
Language	English