DSPF_sp_iir
[Filtering and convolution]

Collaboration diagram for DSPF_sp_iir:

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Detailed Description

void	DSPF_sp_iir (float *restrict y1, const float *x, float *restrict y2, const float *hb, const float *ha, int nr)

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Function Documentation

void DSPF_sp_iir	(	float *restrict	y1,
		const float *	x,
		float *restrict	y2,
		const float *	hb,
		const float *	ha,
		int	nr
	)

The IIR performs an auto-regressive moving-average (ARMA) filter with 4 auto-regressive filter coefficients and 5 moving-average filter coefficients for nr output samples. The output vector is stored in two locations. This routine is used as a high pass filter in the VSELP vocoder. The 4 values in the r1 vector store the initial values of the delays.

Parameters:

	y1[nr+4]	Delay element values (i/p and o/p).
	x[nr]	Pointer to the input array.
	y2[nr+4]	Pointer to the output array.
	hb[5]	Auto-regressive filter coefficients.
	ha[5]	Moving average filter coefficients.
	nr	Number of output samples.

Algorithm:

DSPF_sp_iir_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:

The value of ‘nr’ must be a multiple of 2.
Extraneous loads are allowed in the program.

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