Stand Alone FFT Processor
Description
PDSP16510 PDSP16510A
Stand Alone FFT Processor
Supersedes version in December 1993 Digital Video & DSP IC Handbook, HB3923-1 DS3475 - 4.
4 May 1996
The PDSP16510 performs Forward or Inverse Fast Fourier Transforms on complex or real data sets containing up to 1024 points.
Data and coefficients are each represented by 16 bits, with block floating point arithmetic for increased dynamic range.
An internal RAM is provided which can hold up to 1024 complex data points.
This removes the memory transfer bottleneck, inherent in building block solutions.
Its organisation allows the PDSP16510 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, and the PDSP16510 can be directly connected 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 40MHz system clock used for internal operations.
A 1024 point complex transform can be completed in some 98µs, which is equivalent to throughput rates of 450 million operations per second.
Multiple devices can be connected in parallel in order to increase the sampling rate up to the 40MHz system clock.
Six devices are needed to give the maximum performance with 1024 point transforms.
Either a Hamming or a Blackman-Harris window operator can be internally applied to the incoming real or 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.
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.
DATA INPUT
3 TERM WINDOW OPERATOR
COEFFICIENT ROM
WORKSPACE RAM
WORKSPACE RAM
FOUR DATA PATHS
OUTPUT BUFFER
RESULT OUPUT
Fig.
1.
Block Diagram
FEATURES...
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