DSP_iir_lat
[Filtering and convolution]

Collaboration diagram for DSP_iir_lat:

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Detailed Description

void	DSP_iir_lat (short *x, int nx, const short *restrict k, int nk, int *restrict b, short *r)

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Function Documentation

void DSP_iir_lat	(	short *	x,
		int	nx,
		const short *restrict	k,
		int	nk,
		int *restrict	b,
		short *	r
	)

This routine implements a real all-pole IIR filter in lattice structure (AR lattice). The filter consists of nk lattice stages. Each stage requires one reflection coefficient k and one delay element b. The routine takes an input vector x[] and returns the filter output in r[]. Prior to the first call of the routine the delay elements in b[] should be set to zero. The input data may have to be pre-scaled to avoid overflow or achieve better SNR. The reflections coefficients lie in the range -1.0 < k < 1.0. The order of the coefficients is such that k[nk-1] corresponds to the first lattice stage after the input and k[0] corresponds to the last stage.

Parameters:

	x[nx]	= Input vector (16-bit)
	nx	= Length of input vector.
	k[nk]	= Reflection coefficients in Q.15 format
	nk	= Number of reflection coefficients/lattice stages
	b[nk+1]	= Delay line elements from previous call. Should be initialized to all zeros prior to the first call.
	r[nx]	= Output vector (16-bit)

Algorithm:

DSP_iir_lat_cn.c is the natural C equivalent of the optimized intrinsic C code withoutrestrictions. Note that the intrinsic C code is optimized and restrictions may apply.

Assumptions:

There are no assumptions.

Implementation Notes:

Interruptibility : The code is interruptible.
Endian support : supports both Little and Big endian modes.

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Copyright 2014, Texas Instruments Incorporated