PDSP16515A
PDSP16515A
Stand Alone FFT Processor
Advance Information
DS3922
ISSUE 2.0
April 1999
Ordering Information
Features
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Completely self contained FFT Processor
Pin and functionally compatible with the
PDSP16510A
Expanded width internal RAM supports up to 1024
complex points
18 bit internal data bus with block floating point
arithmetic for increased dynamic range
500 MIP operation gives 87 microsecond
transformation times for 1024 points
Upto45MHzsamplingrateswith multipledevices.
Up to 85dB noise rejection
A choice of internal window operators with no
external ROM provide up to 67dB side lobe
attenuation.
PDSP16515A C0 AC
PDSP16515A C0 GC
PDSP16515A B0 AC
PDSP16515A B0 GC
PDSP16515A A0 AC
PDSP16515A A0 GC
PDSP16515A/MA/GCPR
( Commercial - PGA
Package )
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( Commercial - Leaded
Chip Carrier )
( Industrial - PGA
Package )
( Industrial -
Chip Carrier )
( Military - PGA
Package )
Leaded
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( Military - Leaded Chip
Carrier )
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84 pin PGA or 132 pin surface mount package
( Military - Screened
Leaded Chip Carrier. See separate datasheet for
details )
Associated Products
PDSP16330 Pythagoras Processor.
PDSP16256 Programmable FIR Filter.
PDSP16350 I/Q Splitter / NCO
A 1024 point complex transform can be completed in
some 87µs, which is equivalent to throughput rates of
500 million operations per second. Multiple devices can
be connected in parallel in order to increase the
sampling rate up to the 45MHz system clock. Six
devices are needed to give the maximum performance
with 1024 point transforms.
PDSP16510A Stand Alone FFT Processor
The PDSP16515A performs Forward or Inverse Fast
Fourier Transforms on complex or real data sets
containing up to 1024 points. Data and coefficient input
are both represented by 16 bits. Data is expanded
internally to 18 bits and subject to Block Floating Point
arithmetic to preserve a greater dynamic range.
Either a Hamming or a Blackman-Harris window
operatorcanbeinternallyappliedtotheincomingrealor
complex data. The latter gives 67dB side lobe
attenuation. The operator values are calculated
internally and do not require an external ROM nor do
they incur any time penalty.
An internal RAM is provided which can hold up to 1024
complexdatapoints. Thisremovesthememorytransfer
bottleneck, inherent in building block solutions. Its
organisation allows the PDSP16515A to
simultaneously input new data, transform data stored in
the RAM, and to output previous results. No external
buffering is needed for transforms containing up to 256
points, andthePDSP16515Acanbedirectlyconnected
to an A/D converter to perform continuous transforms.
The user can choose to overlap data blocks by either
0%, 50%, or 75%. Inputs and outputs are synchronous
to the 45MHz system clock used for internal operations.
The increased internal bus size together with block
floating arithmetic produce up to 85dB of noise
rejection.
The device outputs the real and imaginary components
of the frequency bins. These can be directly connected
to the PDSP16330 in order to produce magnitude and
phase values from the complex data.
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