Programming Examples; Channel Encode - Motorola DSP56305 User Manual

13.9

PROGRAMMING EXAMPLES

13.9.1

Channel Encode

;#############################################################################
;
; VCOP Encode with Rate=1/2 and Constraint_length=5
;
; Revised: June '96
;
;#############################################################################
START equ $100
include "ioequz.asm"
include "intequz.asm"
org P:0
jmp START
org P:START
move #$250,r5
move #$200,r6
movep #60,y:M_VCNT
movep #$1c65,y:M_VTPA
movep #$1009,y:M_VCRA
do #61,endd
jclr #8,y:M_VSTR,*
movep x:(r6)+,y:M_VDR
nop
nop
endd
jclr #5,y:M_VSTR,*
rep #122
movep y:M_VDOR,y:(r5)+
jclr #4,y:M_VSTR,*
stop
org x:$200
dc
dc
dc
MOTOROLA
; Output Buffer
; Encoder Input
; 61 input bits to be encoded (example)
; program tap polynomials
; enable Encoding mode
; wait till DREQ
; input data
; pipeline delay
; (see section B-5.1 in DSP56300 Family Manual)
; wait till Proc_Done
; 122 output bits from encoder (Rate=1/2)
; wait till OPC
; Input to the Encoder
$800000
$800000
$7F0000
DSP56305 User's Manual
VITERBI CO-PROCESSOR
Programming Examples
13-37