B.1.2 N Complex Multiplies |
|
|
; cr(I) + jci(I) = ( ar(I) + jai(I) ) * ( br(I) + jbi(I) ), I=1,...,N |
||
; cr(I) = ar(I) * br(I) - ai(I) * bi(I) |
Y1=ar |
|
; ci(I) = ar(I) * bi(I) + ai(I) * br(I) |
Y0=ai |
X0=br, bi |
opt |
cc |
|
|
|
|
|
MOVE |
#AD,R0 |
|
|
; 2 |
2 |
|
MOVE |
#C-1,R2 |
|
|
; 2 |
2 |
|
MOVE |
#BD,R3 |
|
|
; 2 |
2 |
|
MOVE |
|
X:(R2),B |
|
; |
|
dummy move! |
DO |
#NUM,END_DO8 |
|
|
; 2 |
3 |
|
MOVE |
|
X:(R0)+,Y1 |
X:(R3)+,X0 |
; 1 |
1 |
get ar,br |
MPY |
Y1,X0,A |
B,X:(R2)+ |
|
; 1 |
1 |
ar*br, |
|
|
|
|
; |
|
store imag |
MOVE |
|
X:(R0)+,Y0 |
|
; 1 |
1 |
get ai |
MPY |
Y0,X0,B |
X:(R3)+,X0 |
|
; 1 |
1 |
ai*br, get bi |
|
|
|
|
; |
|
get bi |
MACR |
-Y0,X0,A |
|
|
; 1 |
1 |
ar*br-ai*bi |
MACR |
Y1,X0,B |
A,X:(R2)+ |
|
; 1 |
1 |
ar*bi+ai*br, |
END_DO8 |
|
|
|
|
|
store real |
MOVE |
B,X:(R2)+ |
|
|
; 1 |
1 |
|
; |
|
|
|
_______ |
|
|
; |
|
|
Total: |
15 |
6N+11 |
|
B.1.3 Complex Correlation Or Convolution (Complex FIR)
;cr(n) + jci(n) = SUM(I=0,...,N-1)
;{ ( ar(I) + jai(I) ) * ( br(n-I) + jbi(n-I) ) }
; cr(n) = SUM(I=0,...,N-1) |
|
|
Y0=ar |
Y1=br |
|
; { ar(I) * br(n-I) - ai(I) * bi(n-I) } |
|
|
|
||
; ci(n) = SUM(I=0,...,N-1) |
|
|
Y0=ai |
X0=bi |
|
; { ar(I) * bi(n-I) + ai(I) * br(n-I) } |
|
|
|
||
opt |
cc |
|
|
|
|
MOVE |
#AD,R0 |
|
; 2 |
2 |
|
MOVE |
#BD,R3 |
|
; 2 |
2 |
|
CLR |
A |
X:(R0)+,Y0 |
; 1 |
1 |
ar |
CLR |
B |
X:(R3)+,Y1 |
; 1 |
1 |
br |
DO |
#N,END_DOB |
|
; 2 |
3 |
|
MAC |
Y0,Y1,A |
X:(R3)+,X0 |
; 1 |
1 |
ar*br ,ai,bi |
MAC |
Y0,X0,B |
X:(R0)+,Y0 |
; 1 |
1 |
ar*bi |
MAC |
Y0,Y1,B |
X:(R3)+,Y1 |
; 1 |
1 |
ar*bi+ai*br,ar |
MAC |
-Y0,X0,A |
|
; 1 |
1 |
ar*br-ai*bi |
MOVE |
|
X:(R0)+,Y0 |
; 1 |
1 |
|
|
|
|
|
|
|
B-4 |
|
DSP56800 Family Manual |
|
|
|
END_DOB |
|
|
|
|
RND |
A |
; |
1 |
1 |
RND |
B |
; |
1 |
1 |
; |
|
_______ |
||
; |
|
Total: 15 |
5N+11 |
|
B.1.4 Nth Order Power Series (Real, Fractional Data)
;c = SUM(I=0,...,N) { a(I) * b**I }
;= [[[a(n) *b+a(n-1)] *b+a(n-2)]*b+a(n-3)].....
opt |
cc |
|
|
|
|
MOVE |
#BD,R1 |
|
; 2 |
2 |
|
MOVE |
#AD,R0 |
|
; 2 |
2 |
|
MOVE |
|
X:(R1),Y0 |
; 1 |
1 |
b |
MOVE |
Y0,Y1 |
|
; 1 |
1 |
b |
MOVE |
|
X:(R0)+,A |
; 1 |
1 |
get a(n) |
MOVE |
|
X:(R0)+,B |
; 1 |
1 |
get a(n-1) |
DO |
#NUM/2,END_DOC |
|
; 2 |
3 |
|
MAC |
A1,Y0,B |
X:(R0)+,A |
; 1 |
1 |
get a(n-2), and |
|
|
|
|
|
so on |
MAC |
B1,Y1,A |
X:(R0)+,B |
; 1 |
1 |
get a(n-3), and |
|
|
|
|
|
so on |
END_DOC |
|
|
|
|
|
RND |
A |
|
; 1 |
1 |
|
; |
|
|
_______ |
|
|
; |
|
Total: |
13 |
1N+12 |
|
B.1.5 N Cascaded Real Biquad IIR Filters (Direct Form II)
Many digital-filter design packages generate coefficients for direct form II IIR filters. Often, these coefficients are greater in magnitude than 1.0. This implementation is suitable for IIR filters with coefficients greater in magnitude than 1.0 because it allows the user to simply divide all coefficients generated by 2.
;w(n)/2 = x(n)/2 - (a1/2) * w(n-1) - (a2/2) * w(n-2)
;y(n)/2 = w(n)/2 + (b1/2) * w(n-1) + (b2/2) * w(n-2)
;D High Memory Order - w(n-2)1,w(n-1)1,w(n-2)2,w(n-1)2,...
;D Low Memory Order - (a2/2)1,(a1/2)1,(b2/2)1,(b1/2)1,(a2/2)2,...
;This version uses two pointers.
opt |
cc |
|
|
MOVE |
#W,R0 |
; 2 |
2 |
MOVE |
#C,R3 |
; 2 |
2 |
MOVE |
#-1,N |
; 1 |
1 |
MOVE |
x:input,A |
; 1 |
1 |
|
|
|
|
|
DSP Benchmarks |
|
B-5 |