Overview

FIR fract32 filter

Discussion

The FIR Fract32 Module implements a direct convolution N-order Finite Impulse Response filter. The module operates on multiple channels with all channels sharing the same set of filter coefficients. coeffs holds the filter coefficients and is of size numTaps x 1. The coefficients are stored in coeffs in normal order. The state variable array is of size numTaps*numChannels.

Type Definition

typedef struct _ModuleFIRFract32
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32 numTaps;                                // Length of the filter
    INT32 stateIndex;                             // Index of the oldest state variable in the array of state variables
    INT32 postShift;                              // Number of bits to shift
    FLOAT32* coeffs;                              // Coefficient array
    fract32* coeffsfract32;                       // Coefficient array
    fract32* state;                               // State variable array
} ModuleFIRFract32Class;

Variables

Properties

Name	Type	Usage	isHidden	Default value	Range	Units
numTaps	int	const	0	31	1:1:5000	samples
stateIndex	int	state	1	0	Unrestricted
postShift	int	derived	1	1	Unrestricted
coeffs	float*	parameter	0	[31 x 1]	Unrestricted
coeffsfract32	fract32*	derived	0	[32 x 1]	Unrestricted
state	fract32*	state	1	[68 x 1]	Unrestricted

Pins

Input Pins

Name: in

Description: audio input

Data type: fract32

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: out

Description: audio output

Data type: fract32

MATLAB Usage

File Name: fir_fract32_module.m

 M=fir_fract32_module(NAME, L)
 Creates an FIR filter object for use in the Audio Weaver environment.
 The module has a single multi-channel input pin.  Arguments:
    NAME - name of the module.
    L - length of the filter (number of taps).