Table of Contents
Advertisement
move
fmpy
_end_last
B.1.15.3 Radix 4 Decimation in Frequency FFT
fftr4z macro
fftr4z ident
;
; Radix 4 Decimation in Frequency In-Place FFT Routine
;
;
Complex input and output data
;
Real data in X memory
;
Imaginary data in Y memory
;
Normally ordered input data
;
Digit reversed output data
;
Coefficient lookup table
;
Full cycle sinewave in Y memory
;
Coefficient table can be generated by "sinewave" macro.
;
;
; Macro Call - mfftr4z
;
;
points
;
data
;
coef
;
table
;
temp
;
; Cooley-Tukey Radix 4 FFT Algorithm
;
;
; ar,ai
; br,bi
; cr,ci
; dr,di
;
;
;
t1 = ar + cr
;
t2 = ar - cr
MOTOROLA
d8,d7,d3
faddsub.s d4,d0
points,data,coef,table,temp
1,1
points,data,coef,table,temp
number of points (4-16384, power of 4)
starting address of data buffer
starting address of sinewave table
size of sinewave table
starting address of temporary storage area
ar',ai'
Radix 4
br',bi'
Butterfly
cr',ci'
dr',di'
DSP96002 USER'S MANUAL
x:(r6)+n6,d9.s
y:,d8.s
x:(r1)+n1,d6.s
d5.s,y:(r4)+n4
B-19
Advertisement
Table of Contents
