Figure B-4 Lms Adaptive Filter-Double Precision Memory Map; B.1.7.2 Double Precision - Motorola DSP56800 Manual

B.1.7.2 Double Precision
Figure B-4 shows a memory map for this implementation of the double-precision LMS adaptive filter.
Figure B-4. LMS Adaptive Filter—Double Precision Memory Map
opt cc
move #XM,r0
move #N-1,m0
move #2,n
movep x:input,y0
move #H,r3
clr a
move
rep #N-1
mac x0,y0,a
macr x0,y0,a
movep
; (Get d(n), subtract fir output, multiply by "u", put the result in x0.
; This section is application dependent.)
move #H,r3
move r3,r1
move
move
move
do #ntaps,_coefupdate
mac x0,y0,a
move
move
move
B-10
X memory
r0
x(n-N+1)
r1,r3
y0,x:(r0)+
x:(r3)+n,x0
x:(r0)+,y0 x:(r3)+n,x0
a,x:output
x:(r0)+,y0
x:(r3)+,a
x:(r3)+,a0
x:(r0)+,y0
a,x:(r1)+
a0,x:(r1)+
x:(r3)+,a
DSP56800 Family Manual
x(n)
x(n-1)
.
.
c0h
col
c1h
c1l
.
; start of X
; modulo N
; get input sample
; 1 1
; 1 1
; 1 1
; 1 3
; 1 1
; 1 1
; output fir if desired
; 2 2
; 1 1
; 1 1
; 1 1
; 1 1
; 2 3
; 1 1
; 1 1
; 1 1
; 1 1
AA0082
; coefficients
; save x(n)
; get c0
; do fir
; mac; next x
; last tap
; coefficients
; coefficients
; get x(n)
; a1=c0h
; a0=col
; update coef.
u e(n) x(n)+c; fetch
x(n)
save updated c()h
; save updated c()l
; fetch next c()h