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This version (21 Jun 2018 13:15) was approved by Venkatesan Krishnamoorthy.The Previously approved version (14 Mar 2018 07:58) is available.Diff

FFT(ADAU145x)


Click here to return to the Frequency Domain page

There are two kinds of FFT Algorithms
1.Complex FFT
2.Real FFT

Complex FFT

Complex FFT is a block processing module which performs N point complex FFT of the input signal, where N stands for BlockSize.



Input Pins

NameFormat [int/dec/float] - [control/audio]Function Description
Pin 0: Input decimal-audioInput signal to the module

Output Pins

NameFormat [int/dec/float] - [control/audio]Function Description
Pin 0: Output complex-audioOutput signal from the module


Grow Algorithm

Add and Growth are not supported.

GUI Controls


No Dsp parameters.

Context Menu


Right-click on the module to open the context menu window. By default, “Normalize Input(Global Setting)” is Enabled. This is a global setting which determines whether the input is normalized. Click on this to enabled/disabled the “Normalize Input(Global Setting)” option. This leads to re-compile the project.

Algorithm Description


This module computes the Complex FFT of Real input Signals and generates complex FFT output. Output blocksize is double the input Blocksize for this module.

Example

In the example shown below, complex magnitude of the FFT outputs of Inputs 1 and 2 are computed.

Real FFT

Real FFT is a block processing module which computes the FFT of real signals.It is for reduced memory and Mips.

Input Pins

NameFormat [int/dec/float] - [control/audio]Function Description
Pin 0: Input decimal-audioInput signal to the module

Output Pins

NameFormat [int/dec/float] - [control/audio]Function Description
Pin 0: Output complex-audioOutput signal from the module


Context Menu


Right-click on the module to open the context menu window. By default, “Normalize Input(Global Setting)” is Enabled. This is a global setting which determines whether the input is normalized. Click on this to enabled/disabled the “Normalize Input(Global Setting)” option. This leads to re-compile the project.

Right-click on the module to open the context menu window, Click on the file type, two options Mips optimized and Memory optimized will be displayed.Select Mips optimized for Mips optimmized algorithm and Select Memory optimized for Memory optimized Algorithm. Change of FFT type leads to re-compile the project.

Grow Algorithm

Add and Growth are not supported.

DSP Parameter Information

GUI Control NameCompiler NameFunction Description

Real FFT - Memory optimized:-

NA splitCoeffsASine coefficients
NA splitCoeffsBCosine coefficients

Real FFT - Mips optimized:-

NA splitCoeffsAN*Sine coefficients
NA splitCoeffsBN*Cosine coefficients


Note:N stands for BlockSize/2

Algorithm Description

This module computes the Real FFT of Real input signals for reduced memory and Mips. Since FFT of real signals has complex conjugate symmetry, only first half of the FFT output is computed. Input and output Blocksizes are the same for this module.


Example

In the example shown below, complex magnitude of the FFT outputs of Real Inputs 1 and 2 are computed.

Supported IC's

1. ADAU145x

resources/tools-software/sigmastudio/toolbox/frequencydomain/fft.txt · Last modified: 21 Jun 2018 13:13 by Sanjeeva Reddy