Texas Instruments TMS320C28x User Manual

Addressing Modes Select Bit (AMODE)
5-6
Table 5−1. Addressing Modes for “loc16” or “loc32”
AMODE = 1AMODE = 0
”loc16/loc32” Syntax8-Bit Decode”loc16/loc32” Syntax8-Bit Decode
16-Bit Register Addressing Modes (AR0 to AR7, AH, AL, PH, PL, TH, SP):
1 0 100 AAA
1 0 101 000
1 0 101 001
1 0 101 010
1 0 101 011
1 0 101 100
1 0 101 101
@ARn
@AH
@AL
@PH
@PL
@TH
@SP
1 0 100 AAA
1 0 101 000
1 0 101 001
1 0 101 010
1 0 101 011
1 0 101 100
1 0 101 101
@ARn
@AH
@AL
@PH
@PL
@TH
@SP
In the ”C28x Indirect” addressing modes, the auxiliary register pointer used in
the addressing mode is implicitly specified. In the ”C2xLP Indirect” addressing
modes, a 3-bit pointer called the auxiliary register pointer (ARP) is used to se-
lect which of the auxiliary registers is currently used and which pointer is used
in the next operation.
The examples below illustrate the differences between the ”C28x Indirect” and
”C2xLP Indirect” addressing modes:
- ADD AL,*XAR4++
Read the contents of 16-bit memory location pointed to by register XAR4,
add the contents to AL register. Post-increment the contents of XAR4 by 1.
- ADD AL,*++
Assume ARP pointer in ST1 contains the value 4. Read the contents of
16-bit memory location pointed to by register XAR4, add the contents to
AL register. Post-increment the contents of XAR4 by 1.
- ADD AL,*++,ARP5
Assume ARP pointer in ST1 contains the value 4. Read the contents of
16-bit memory location pointed to by register XAR4, add the contents to
AL register. Post-increment the contents of XAR4 by 1. Set the ARP point-
er to 5. Now it points to XAR5.
On the C28x instruction syntax, the destination operand is always on the left
and the source operands are always on the right.

Texas Instruments TMS320C28x Specifications

General

Brand	Texas Instruments
Model	TMS320C28x
Category	Processor
Language	English