DSPF_sp_iirlat
[Filtering and convolution]

Collaboration diagram for DSPF_sp_iirlat:

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Detailed Description

void	DSPF_sp_iirlat (const float *x, int nx, const float *restrict k, int nk, float *restrict b, float *restrict y)

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Function Documentation

void DSPF_sp_iirlat	(	const float *	x,
		int	nx,
		const float *restrict	k,
		int	nk,
		float *restrict	b,
		float *restrict	y
	)

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 y[]. 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.
	nx	Length of input vector.
	k[nk]	Reflection coefficients.
	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.
	y[nx]	Output vector.

Algorithm:

DSPF_sp_iirlat_cn.c is the natural C equivalent of the optimized linear assembly code without restrictions. Note that the linear assembly code is optimized and restrictions may apply.

Assumptions:

nx > 0, nk is a multiple of 4 and >= 4.
The arrays k and b are double-word aligned.

Implementation Notes:

Interruptibility: The code is interruptible.
Endian Support: The code supports both big and little endian modes.

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Copyright 2014, Texas Instruments Incorporated