Figure B-3 Lms Adaptive Filter-Single Precision Memory Map; B.1.7.1 Single Precision - Motorola DSP56800 Manual

B.1.7.1 Single Precision
Figure B-3 shows a memory map for this implementation of the single-precision LMS adaptive filter.
Figure B-3. LMS Adaptive Filter—Single 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 y0,x0,a
macr y0,x0,a
movep
; (Get d(n), subtract fir output, multiply by "u", put the result in y1.
; This section is application dependent.)
move #H,r3
move r3,r1
move
move
do #ntaps,_coefupdate
macr y1,y0,a
tfr x0,a
_coefupdate
move
;
;
r0
r3,r1
y0,x:(r0)+
x:(r3)+,x0
x:(r0)+,y0 x:(r3)+,x0
a,x:output
x:(r0)+,y0
x:(r3)+,a
x:(r0)+,y0 x:(r3)+,x0
a,x:(r1)+
x:(r0)+n,y0
Total:
DSP Benchmarks
X memory
x(n)
x(n-1)
.
.
x(n-N+1)
c0
c1
c1
.
c(N-1)
; start of X
; modulo N
; adjustment for filtering
; get input sample
; 2 2 coefficients
; 1 1 save x(n)
; 1 1 get c0
; 1 3 do fir
; 1 1
; 1 1 last tap
; 1 1 output fir if desired
; 2 2 coefficients
; 1 1 coefficients
; 1 1 get x(n)
; 1 1 a=c0
; 2 3 update coef.
; 1 1
; 1 1 copy c,
; 1 1 update r0
________
18 3N+18
AA0081
B-9