Motorola DSP96002 - Manual (Page 555)

B-36 DSP96002 USER’S MANUAL MOTOROLA
SINGLE SECTION
EQUATIONS:
t’=t*q-k*s
u’=t*k+s*q
t’
→
t
output=sum (w*u’)
DSP56000 IMPLEMENTATION
Program ICycles
Words
move #coef,r0 ;point to coefficients
move #3*N,m0 ;mod on coefficients
move #state,r4 ;point to state variables
move #N,m4 ;mod on filter states
movep y:datin,y0 ;get input sample
move x:(r0)+,x1 ;get first Q in table 1 1
do #order,_endnlat 2 3
mpy x1,y0,a x:(r0)+,x0 y:(r4),y1 ;q*t, get k, get s 1 1
macr -x0,y1,a b,y:(r4)+ ;q*t-k*s, save new s 1 1
mpy x0,y0,b a,y0 ;k*t, set t’ 1 1
macr x1,y1,b x:(r0)+,x1 ;k*t+q*s, get next q 1 1
_endnlat
move b,y:(r4)+ ;sv scnd lst st 1 1
move a,y:(r4)+ ;save last state 1 1
clr a y:(r4)+,y0 ;clr acc, get fst st 1 1
rep #order ;do fir taps 1 2
mac x1,y0,a x:(r0)+,x1 y:(r4)+,y0 1 1
macr x1,y0,a (r4)+ ;rnd, adj pointer 1 1
movep a,y:datout ;output sample
--- ---
Totals: 13 5N+10
DSP96002 IMPLEMENTATION
∑
∑
Z
-1
t’
u’
s
w
k k’
t
q
q
u