FFT/IFFT High Performance 64-Point
Features
- High performance
- No external memory required
- Easy to use
Block Diagram
Figure 1 shows the block diagram for the Amphion high performance 64-point fast Fourier transform (FFT)/inverse fast Fourier transform (IFFT) megafunction.
| Figure 1. FFT/IFFT High Performance 64-Point Block Diagram |
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Description
The Amphion high performance 64-point FFT/IFFT megafunction, FFT64HP, performs forward or inverse FFT functions on complex data containing 64 points according to the equations below:
Data is loaded into the workspace RAM in normal sequential order. The transformed data comes out from the function in radix-4 digitally-reversed order with the index indicated by output QIX.
The FFT64HP megafunction is based on the radix-4 decimation in frequency (DIF) algorithm. It performs the computation concurrently in three highly pipelined cascaded stages, as illustrated in Figure 29. The FFT64P megafunction is capable of processing continuous input data and contains all the necessary circuits to support this continuous processing.
The internal complex programmable logic device (CPLD) memory is utilized and the whole circuit is on a single device. Both the input and output are complex numbers in the two’s complement format. The input wordlength is 9 bits and the output wordlength is 12 bits. The twiddle factors and internal commutation data wordlengths are 12 bits.
The function can accept continuous input data, i.e., a 64-point data block every 64 clock cycles. When clocked at 54 MHz, the function achieves continuous computation speed of approximately 1.19 ms. The computation has a latency of 174 clock cycles.
Device Utilization Example
Table 1 lists the typical device utilization results for the megafunction.
| Table 1. Typical Device Utilization for the Megafunction |
| Device |
Speed Grade |
Utilization |
Performance
(fMAX) |
Parameter Setting |
| Logic Cells |
EABs (1) |
| EPF10K100ARC |
-1 |
3,963 |
12 |
13.88ns,
72 MHz |
Contact Amphion |
Note:
- EABs = Embedded array blocks
Contact Information
For additional information, you can contact Amphion Semiconductor, Ltd. at:
Amphion Semiconductor, Ltd.
51 Malone Road
Belfast, BT9 6RY
Northern Ireland
Tel. +44 28 9050-4000
Fax +44 28 9050-4001
Email: info@amphion.com
URL: http://www.amphion.com
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