Motorola DSP96002 - Manual (Page 530)

MOTOROLA DSP96002 USER’S MANUAL B-11
DSP96002 IMPLEMENTATION
ProgramICycles
Words
move #$ffffffff,m0 2 2
move m0,m4 1 1
move m0,m1 1 1
move #data,r0 2 2
move r0,r1 1 1
move #coef,r4 2 2
movep x:input,d0.s 1 2
fclr d1 x:(r0)+,d4.s y:(r4)+,d6.s 1 1
do #n,end 2 3
fmpy d4,d6,d1 fadd.s d1,d0 x:(r0)+,d5.s y:(r4)+,d6.s 1 1
fmpy d5,d6,d1 fsub.s d1,d0 d5.s,x:(r1)+ y:(r4)+,d6.s 1 1
fmpy d4,d6,d1 fsub.s d1,d0 x:(r0)+,d4.s y:(r4)+,d6.s 1 1
fmpy d5,d6,d1 fadd.s d1,d0 d0.s,x:(r1)+ y:(r4)+,d6.s 1 1
end
fadd.s d1,d0 1 1
movep d0.s,x:output 1 2
--- ---
Totals: 19 4N+18
(17 4N+16)
B.1.15 Fast Fourier Transforms
B.1.15.1 Radix 2 Decimation in Time FFT
metr2a macro points,data,coef,coefsize
metr2a ident 1,4
;
;Radix 2 Decimation in Time In-Place Fast Fourier Transform Routine
;
; Complex input and output data
; Real data in X memory
; Imaginary data in Y memory
; Normally ordered input data
; Bit reversed output data
;
; Coefficient lookup table
; +Cosine value (1/2 cycle) in X memory