Motorola DSP96002 - Manual (Page 631)

B-112 DSP96002 USER’S MANUAL MOTOROLA
page 132,60,1,1
;
; Implements the Walsh-Hadamard Transform
;
iord equ 4 ;order of transform=log2(npoints)
n equ 1<<iord ;length of transform
org x:$1000
data
dc 0.0000000E+00
dc 2.000000
dc 3.000000
dc 8.000000
dc 9.000000
dc 12.00000
dc 15.00000
dc 19.00000
dc 20.00000
dc 22.00000
dc 23.00000
dc 24.00000
dc 25.00000
dc 26.00000
dc 27.00000
dc 28.00000
org p:$100
start
move #data,r0 ;point to upper leg
move #data+n/2,r4 ;point to lower leg
do #n/4,_firststage ;do first stage. split into X and Y
move x:(r0)+,d0.s ;get upper leg of bfly 1
move x:(r4)+,d1.s ;get lower leg of bfly 1
faddsub.s d0,d1 x:(r0)-,d2.s ;get upper leg of bfly 2
move x:(r4)+,d3.s ;get lower leg of bfly 2
faddsub.s d2,d3 d1.s,x:(r0) ;save sum 1
move d0.s,y:(r0)+ ;save dif 1
move d3.s,x:(r0) ;save sum 2