readme_fft_fxp16.txt

TigerSharc TS201 32-bit floating point FFT routine

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  ADSP-TS101S and ADSP-TS201S Fast Fourier Transforms in fixed point format

Analog Devices, Inc.
DSP Division
Three Technology Way
P.O. Box 9106
Norwood, MA 02062

February, 2004 - PM

The file fft16 contains Assembly and C source code for performing
Fast Fourier Transforms in fixed point format

#defines have been added allowing the same source code to be used on both an ADSP-TS101S
or an ADSP-TS201S EZ-Kit.

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1. fixed point FFT


The file fft_fxp16.zip contains Assembly and C source code for performing
optimized Complex Fixed Point Fast Fourier Transform.

Files contained in this directory:

inputs folder			contains the input points files: inputN.dat, N=64, 128,...,32768
outputs folder			contains the fft output files output_N.dat obtained from the DSP and
    				the files output_N_matlab.dat obtained by performing the fft in Matlab.
fft_N_TS201.tcl			Tcl scripts used to build, execute and save the fft results
fft_N_Ts101.tcl 		Tcl scripts used to build, execute and save the fft results
twiddles folder			contains the twiddle factor specific for each number of	points N: twidN.dat
ADSP-TS201_C.ldf		Linker Description File for TS201
ADSP-TS101_C.ldf		Linker Description File for TS101
main.c				main program to call fft16.asm file.
fft_fxp16.asm			Optimized complex C-callable fixed point FFT.
variables.asm			Twiddle factor table
FFTDef.h			Define
ini_cache.h			contains the program that preloads the cache with the twiddless
cache_macros.h			contains the program used to initialize the cache
generate_number.m		matlab program that produces input files to FFT
generate_twiddles.m		matlab program that produces the twiddles factors for various FFTs
FFT_fxp16.m			matlab program that tests the outputs of the assembly program
cvt2hex.m			matlab utilities
cvt2real.m			matlab utilities
save_fixed.m			matlab utilities
twiddles.m			matlab utilities
FFT_fxp16_Project_rev02.pdf	Description of Fixed Point FFT Example


Project options for ADSP-TS101S EZ-Kit: 
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Please refer to the VisualDSP++ release notes and the 
ADSP-TS101S anomaly listings for full details of the following switch usage, 
operation and silicon revision requirements

Assembler/Compiler switches to be used in the assembler and 
compiler property pages' Additional Options fields

'-default-branch-np'	Required for TS101S Rev 0.1 silicon. 
						Use in BOTH compiler AND Assembler property 
						page 'Additional Options' field.

"-align-branch-lines'	Required for TS101S Rev 0.1 and 0.2 silicon". 
						Although a specific example may not contain a 
						"jump(P)", to keep generality the switch is 
						required for all silicon versions. Use only 
						in Assembler property page 'Additional Options'
						field.


If any example code projects are built/rebuilt for the above mentioned 
silicon revisions, these switches must be used. The same holds true for 
user created code sets.