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FIR Filter Pool

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The FIR Filter Pool module is an enhanced version of the standard FIR filter allowing users to select an input and a FIR coefficient set and route the selected input through the coefficient set to a particular output. It also enables the user to invert the output and reverse the coefficient set. The module also enables the user to define custom filter and input labels using the filter pool form.

Input Pins

NameFormat [int/dec/float] - [control/audio]Function Description
Pin 0: Inputdecimal(ADAU145x)- audio
float(214xx) - audio
Input signal to be filtered

Output Pins

NameFormat [int/dec/float] - [control/audio]Function Description
Pin 0: Outputdecimal(ADAU145x)- audio
float(214xx) - audio
The filtered output

Grow Algorithm

The module supports growth functionality. Add is not supported.

GUI Controls

GUI Control NameDefault ValueRangeFunction Description
Tap Size1010-10000This pre/post scalar determines the number of taps of the FIR filter
Input Selection Combo box00-31This pre/post scalar determines the selected input for a particular output
Filter Selection Combo box00-15This pre/post scalar determines the selected FIR filter coefficient set for a particular output
Reverse Selection 00/1This pre/post scalar determines the if the selected FIR filter coefficient set for a particular output is to be reversed, the set is accessed in reverse order when the tiny circle is enabled(1)
Invert Selection 00/1This pre/post scalar determines the if the particular output is to be inverted, the output is inverted(-output) when the tiny circle is enabled(1)

DSP Parameter Information

GUI Control NameCompiler NameFunction Description
NumFiltFirFiltPoolS300Alg1Numfilt(ADAU145x) FirFiltPoolBlkAlg1Numfilt(214xx)The Number of filter coefficient sets
TapSizeFirFiltPoolS300Alg1TapSize(ADAU145x) FirFiltPoolBlkAlg1TapSize(214xx)
The Number of filter taps in each coefficient set
InIndxFirFiltPoolS300Alg1InIndx(ADAU145x) FirFiltPoolBlkAlg1InIndx(214xx)
The selected input index
FiltIndxFirFiltPoolS300Alg1FIltIndx(ADAU145x) FirFiltPoolBlkAlg1FiltIndx(214xx)
The Selected filter coefficient set index
RevIndxFirFiltPoolS300Alg1RevIndx(ADAU145x) FirFiltPoolBlkAlg1RevIndx(214xx)
The Selected Reverse Index, if set(value=1), the coefficient access order for filtering is reversed
InvIndxFirFiltPoolS300Alg1InvIndx(ADAU145x) FirFiltPoolBlkAlg1InvIndx(214xx)
The Selected Invert Index, if set(value=1), the output value is negated

Algorithm Description

The Algorithm implements a FIR filter of order N, having N+1 filter taps. Multiple coefficient sets can be added to the module, enabling the routing of multiple inputs through multiple independent FIR filters to a given output selection line. The FIR Filter Pool form has multiple tabs each having a particular routing selection and parameters between the inputs and outputs. The algorithm implements invert functionality which inverts the output samples and Reverse which access the loaded filter coefficient set in reverse for a particular selection.


The example shows The module configured to two inputs and three output channels with three independent FIR Filter coefficient sets. The three coefficients are Low pass FIR filters with cutoffs 2.4KHz,4.8kHz and 7.2KHz. The output plots for the configuration are shown below.

Supported IC's

1. ADAU145x
2. 214XX 3. 213xx 4. SC58x

resources/tools-software/sigmastudio/toolbox/filters/firfilterpool.1498814717.txt.gz · Last modified: 30 Jun 2017 11:25 by Prasad Kamath