IPR-FFT Altera, IPR-FFT Datasheet - Page 31

• Manufacturer Part Number: IPR-FFT
• Description: IP CORE Renewal Of IP-FFT
• Manufacturer: Altera
• Type: MegaCorer

Specifications of IPR-FFT

• Software Application: IP CORE, DSP Filters And Transforms
• Supported Families: Arria GX, Cyclone, HardCopy, Stratix
• Features: Bit-Accurate MATLAB Models, Radix-4 And Mixed Radix-4/2 Implementations
• Core Architecture: FPGA
• Core Sub-architecture: Arria, Cyclone, Stratix
• Rohs Compliant: NA
• Function: Fast Fourier Transform Processor
• License: Renewal License
• Lead Free Status / RoHS Status: na
• Lead Free Status / RoHS Status: na

Chapter 2: Getting Started
Simulate the Design
© December 2010 Altera Corporation
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Fixed Transform Architectures
The FFT MegaCore function outputs a bit-accurate MATLAB model <variation
name>_model.m, which you can use to model the behavior of your custom FFT
variation in the MATLAB software. The model takes a complex vector as input and it
outputs the transform-domain complex vector and corresponding block exponent
values. The length and direction of the transform (FFT/IFFT) are also passed as inputs
to the model.
If the input vector length is an integral multiple of N, the transform length, the length
of the output vector(s) is equal to the length of the input vector. However, if the input
vector is not an integral multiple of N, it is zero-padded to extend the length to be so.
For additional information about exponent values, refer to
Floating Point
The wizard also creates the MATLAB testbench file <variation name>_tb.m. This file
creates the stimuli for the MATLAB model by reading the input complex random data
from IP Toolbench-generated.
If you selected Floating point data representation, the input data is generated in
hexadecimal format.
To model your fixed-transform architecture FFT MegaCore function variation in the
MATLAB software, follow these steps:
1. Run the MATLAB software.
2. In the MATLAB command window, change to the working directory for your
3. Perform the simulation:
For more information about MATLAB and Simulink, refer to the MathWorks web site
at www.mathworks.com.
Variable Streaming Architecture
The FFT MegaCore function outputs a bit-accurate MATLAB model <variation
name>_model.m, which you can use to model the behavior of your custom FFT
variation in the MATLAB software. The model takes a complex vector as input and it
outputs the transform-domain complex vector. The lengths and direction of the
transforms (FFT/IFFT) (specified as one entry per block) are also passed as an input to
the model.
project.
a. Type help <variation name>_model at the command prompt to view the
b. Run the provided testbench by typing the name of the testbench, <variation
input and output vectors that are required to run the MATLAB model as a
standalone M-function. Create your input vector and make a function call to
<variation name>_model. For example:
or
name>_tb at the command prompt.
N=2048;
INVERSE = 0; % 0 => FFT 1=> IFFT
x = (2^12)*rand(1,N) + j*(2^12)*rand(1,N);
[y,e] = <variation name>_model(x,N,INVERSE);
Scaling.
AN 404: FFT/IFFT Block
FFT MegaCore Function User Guide
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