/* ======================================================================== */
/* TEXAS INSTRUMENTS, INC. */
/* */
/* DSPLIB DSP Signal Processing Library */
/* */
/* Release: Version 1.02 */
/* CVS Revision: 1.5 Sun Mar 17 11:25:23 2002 (UTC) */
/* Snapshot date: 18-Apr-2002 */
/* */
/* This library contains proprietary intellectual property of Texas */
/* Instruments, Inc. The library and its source code are protected by */
/* various copyrights, and portions may also be protected by patents or */
/* other legal protections. */
/* */
/* This software is licensed for use with Texas Instruments TMS320 */
/* family DSPs. This license was provided to you prior to installing */
/* the software. You may review this license by consulting the file */
/* TI_license.PDF which accompanies the files in this library. */
/* ------------------------------------------------------------------------ */
/* Copyright (C) 2002 Texas Instruments, Incorporated. */
/* All Rights Reserved. */
/* ======================================================================== */
/* ======================================================================== */
/* */
/* TEXAS INSTRUMENTS, INC. */
/* */
/* NAME */
/* DSP_fir_gen */
/* */
/* REVISION DATE */
/* 15-Feb-2002 */
/* */
/* USAGE */
/* This routine is C-callable and can be called as: */
/* */
/* void DSP_fir_gen */
/* ( */
/* const short *restrict x, */
/* const short *restrict h, */
/* short *restrict r, */
/* int nh, */
/* int nr */
/* ) */
/* */
/* x[nr+nh-1] : Input array */
/* h[nh] : Coefficient array. Must be in reverse order. */
/* r[nr] : Output array */
/* nh : Number of coefficients. Must be >= 5. */
/* nr : Number of output samples */
/* */
/* DESCRIPTION */
/* Computes a real FIR filter (direct-form) using coefficients stored */
/* in vector h. The coefficients have to be arranged in reverse */
/* order. The real data input is stored in vector x. The filter */
/* output result is stored in vector r. It operates on 16-bit data */
/* with a 32-bit accumulate. The filter is nr output samples and nh */
/* coefficients. */
/* */
/* C CODE */
/* void DSP_fir_gen */
/* ( */
/* const short *restrict x, */
/* const short *restrict h, */
/* short *restrict r, */
/* int nh, */
/* int nr */
/* ) */
/* { */
/* int i, j, sum; */
/* */
/* for (j = 0; j < nr; j++) */
/* { */
/* sum = 0; */
/* for (i = 0; i < nh; i++) */
/* sum += x[i + j] * h[i]; */
/* r[j] = sum >> 15; */
/* } */
/* } */
/* */
/* TECHNIQUES */
/* The inner loop is unrolled four times, but the last three */
/* accumulates are executed conditionally to allow for a number of */
/* coefficients that is not a multiple of four. The outer loop is */
/* unrolled twice, but the last store is executed conditionally to */
/* allow for a number of output samples that is not a multiple of */
/* two. Both the inner and outer loops are software pipelined. */
/* */
/* ASSUMPTIONS */
/* nh must be >= 5. */
/* */
/* MEMORY NOTE */
/* No memory bank hits under any conditions. */
/* */
/* NOTES */
/* This function is interrupt-tolerant but not interruptible. */
/* This function is endian neutral. */
/* */
/* CYCLES */
/* (4 * ceil(nh/4) + 9) * ceil(nr/2) + 18 */
/* */
/* For nh = 13, nr = 19: 268 cycles */
/* */
/* CODESIZE */
/* 640 bytes */
/* */
/* ------------------------------------------------------------------------ */
/* Copyright (c) 2002 Texas Instruments, Incorporated. */
/* All Rights Reserved. */
/* ======================================================================== */
#ifndef DSP_FIR_GEN_H_
#define DSP_FIR_GEN_H_ 1
void DSP_fir_gen
(
const short *restrict x,
const short *restrict h,
short *restrict r,
int nh,
int nr
);
#endif
/* ======================================================================== */
/* End of file: dsp_fir_gen.h */
/* ------------------------------------------------------------------------ */
/* Copyright (c) 2002 Texas Instruments, Incorporated. */
/* All Rights Reserved. */
/* ======================================================================== */