Texas Instruments C28 Series Student Guide

Multiplier
Single repeat instruction (RPT) is used to reduce code size and speed up many operations in the
DSP application. Some of the most popular operations that use the RPT instruction to perform
multiple taps digital filters or perform block of data transfer.
MAC Instruction
Sum-of-Products: RPT / MAC
∑
=
=
19
0n
nn
axy
XAR1++
XAR1++
X0
X0
X1
X1
...
...
X19
X19
MOV T,loc16
ADD ACC,P
MPY P,T,loc16
MOVA T,loc16
ACC+=P
T=*ARn++
P=T*(*ARn++)
MAC
{
Zero ACC & P
Zero ACC & P
Repeat single
Repeat single
Dual operand
Dual operand
last ADD
last ADD
ZAPA
ZAPA
RPT
RPT
#19
#19
||
||
MAC
MAC
P,*XAR1++,*XAR7++
P,*XAR1++,*XAR7++
ADDL
ADDL
ACC,P<<PM
ACC,P<<PM
x
x
.
.
usect
usect
“sample”,20
“sample”,20
y
y
.
.
usect
usect
“result”,2
“result”,2
.sect “coefficient”
.sect “coefficient”
a0:
a0:
.word
.word
0x0101
0x0101
.word
.word
0x0202
0x0202
• • •
• • •
.word
.word
0x2020
0x2020
.sect “code”
.sect “code”
SOP:
SOP:
SPM
SPM
0
0
MOVW
MOVW
DP,#y
DP,#y
MOVL
MOVL
XAR1,#x
XAR1,#x
MOVL
MOVL
XAR7,#a0
XAR7,#a0
MOVL
MOVL
@y,ACC
@y,ACC
B SOP,UNC
B SOP,UNC
XAR7++
A0
A1
...
A19
Second operand
Second operand
must use XAR7
must use XAR7
C - 12 C28x - Appendix C - Assembly Programming

Texas Instruments C28 Series Specifications

General

Brand	Texas Instruments
Model	C28 Series
Category	Computer Hardware
Language	English