dsp56000 Freescale Semiconductor, Inc, dsp56000 Datasheet - Page 614

• Manufacturer Part Number: dsp56000
• Description: 24-bit Digital Signal Processor Family Manual
• Manufacturer: Freescale Semiconductor, Inc

B - 10
;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
fftr2a
;
;Radix-2 Decimation-In-Time In-Place FFT Routine
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;Macro Call — ffr2a
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;Alters Data ALU Registers
;
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;Alters Address Registers
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‘
‘Alters Program Control Registers
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;Uses 6 locations on System Stack
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Complex input and output data
Normally ordered input data
Bit reversed output data
Figure B-2 Radix 2, In-Place, Decimation-In-Time FFT (Sheet 1 of 2)
-Cosine values in X memory
Imaginary data in Y memory
-Sine values in Y memory
Real data in X memory
Coefficient lookup table
macro
ident
points
data
coef
x1
a2
b2
r0
r1
r4
r5
r6
pc
points,data,coef
points,data,coef
1,1
x0
a1
b1
n0
n1
n2
n4
n5
n6
sr
Freescale Semiconductor, Inc.
For More Information On This Product,
Version 1.1
BENCHMARK PROGRAMS
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number of points (2-32768, power of 2)
start of data buffer
start of sine/cosine table
y1
a0
b0
m0
m1
m4
m5
m6
y0
a
b
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