Overview

Sparse FIR filter in which most coefficients equal zero

Discussion

This module implements a sparse FIR filter in which most coefficients are equal to zero. The filter is implemented using a tap delay line rather than a traditional FIR filter. The number of output taps (NUMTAPS) is specified at instantiation time. For each tap, you specify the delay time (tapDelay array) and the weighting coefficient (tapCoeffs array). Delays are specified in units of samples.

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The tapCoeffs and tapDelay array are always allocated in internal DM memory.

Type Definition

typedef struct _ModuleFIRSparse
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32 numTaps;                                // Number of non-zero coefficients (taps) in the filter
    INT32 maxDelay;                               // Maximum delay that can be realized, in samples
    INT32 stateHeap;                              // Heap in which to allocate memory
    INT32 stateIndex;                             // Index of the oldest state variable in the array of state variables
    INT32* tapDelay;                              // Current delay per channel
    FLOAT32* tapCoeffs;                           // Coefficient applied to each tap output
    FLOAT32* state;                               // State variable array
} ModuleFIRSparseClass;

Variables

Properties

Pins

Input Pins

Name: in

Description: audio input

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Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: out

Description: audio output

Data type: float

Scratch Pins

Channel count: 1

Block size: 32

Sample rate: 48000

MATLAB Usage

File Name: fir_sparse_module.m

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