B-2 Radix 2, In-Place, Decimation-In-Time Fft - Motorola DSP56000 Manual

;This program originally available on the Motorola DSP bulletin board.
;It is provided under a DISCLAIMER OF WARRANTY available from
;Motorola DSP Operation, 6501 William Cannon Drive, Austin, TX, 78735
;
;Radix-2, In-Place, Decimation-In-Time FFT (smallest code size).
;
;Last Update 30 Sep 86
;
fftr2a macro
fftr2a ident
;
;Radix-2 Decimation-In-Time In-Place FFT 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 values in X memory
; -Sine values in Y memory
;
;Macro Call — ffr2a
;
; points
; data
; coef
;
;Alters Data ALU Registers
; x1
; a2
; b2
;
;Alters Address Registers
; r0
; r1
;
;
; r4
; r5
; r6
'
'Alters Program Control Registers
; pc
;
;Uses 6 locations on System Stack
;
Figure B-2 Radix 2, In-Place, Decimation-In-Time FFT (Sheet 1 of 2)
B - 10
BENCHMARK PROGRAMS
Version 1.1
points,data,coef
1,1
points,data,coef
number of points (2-32768, power of 2)
start of data buffer
start of sine/cosine table
x0 y1
a1 a0
b1 b0
n0 m0
n1 m1
n2
n4 m4
n5 m5
n6 m6
sr
BENCHMARK PROGRAMS
y0
a
b
MOTOROLA