High-performance Low-memory Mixed Radix FFT

Overview

This FFT is an efficient implementation of the Decimation in Frequency (DIF) Cooley-Tukey FFT. Using low FPGA/ASIC resources and a high clock speed, this design manages high throughput by careful design optimization. This results in an IP core well balanced between logic and throughput.

The FFT IP consists of two separate variants:
A complex valued IFFT/FFT.
A real valued IFFT/FFT.



The real valued FFT uses a half size transform and a combining pass to generate the full transform. This means that the core has only half the scratch memory and cycle count of the complex valued transform.

EnSilica has a comprehensive range of FFT IP cores, these cores can be configured to replace the AMD FFT LogiCORE™ IP or FFT Intel® FPGA IP Core when migrating an FPGA design to ASIC technology.

Key Features

  • Real or Complex valued IFFT/FFT options
  • Per transform selection of FFT size from 8 to 32768 points
  • Per transform selection of FFT or IFFT
  • Efficient mixed radix 4/2 dragonfly for low cycle count
  • Block floating point scaling ensures excellent dynamic range
  • Data and twiddle bit widths are parameterized
  • IEEE-754 convergent rounding after twiddle multiplications
  • 1/8 twiddle table storage for lowest ROM requirements
  • Choice of interfacing options

Applications

  • OFDM system such as :
    • DVB/DAB
    • IEEE802.11a
    • IEEE802.11n
    • IEEE802.16

Deliverables

  • RTL
  • Testbench
  • Synthesis scripts
  • Documentation
  • MATLAB and C++ bit exact model

Technical Specifications

Foundry, Node
Any
Maturity
Production
Availability
Immediate
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Semiconductor IP