;* ======================================================================== *;
;* TEXAS INSTRUMENTS, INC. *;
;* *;
;* DSPLIB DSP Signal Processing Library *;
;* *;
;* Release: Version 1.02 *;
;* CVS Revision: 1.4 Fri Mar 22 01:51:54 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_r4 *
* *
* REVISION DATE *
* 25-Feb-2002 *
* *
* USAGE *
* This routine is C-callable and can be called as: *
* *
* void DSP_fir_r4 *
* ( *
* const short *x, *
* const short *h, *
* short *r, *
* int nh, *
* int nr *
* ); *
* *
* x[nr+nh-1]: Input samples. *
* h[nh] : Filter coefficients. Must be in reverse order. *
* r[nr] : Output samples. *
* nh : Number of filter coefficients. *
* Must be multiple of 4 and >= 8. *
* nr : Number of output samples. *
* Must be multiple of 2. *
* *
* DESCRIPTION *
* Computes a real FIR filter (direct-form) using coefficients stored *
* in vector h. The real data input is stored in vector x. The *
* filter output is stored in vector r. The filter computes nr output *
* samples and nh coefficients. It operates on 16-bit data with a *
* 32-bit accumulate. *
* *
* C CODE *
* void DSP_fir_r4 *
* ( *
* const short *x, *
* const short *h, *
* short *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; *
* } *
* } *
* *
* *
* ASSUMPTIONS *
* nh must be a multiple of 4 and >= 8. *
* nr must be a multiple of 2 and >= 2. *
* *
* MEMORY NOTE *
* No memory bank hits under any conditions. *
* This code is Endian neutral. *
* *
* TECHNIQUES *
* The assembly routine performs 2 output samples at a time. *
* The inner loop is unrolled four times. The outer loop is unrolled *
* twice. Both the inner and outer loops are software pipelined. *
* *
* CYCLES *
* (8 + nh) * nr/2 + 14 *
* *
* CODESIZE *
* 544 bytes *
* *
* *
* ------------------------------------------------------------------------- *
* Copyright (c) 2002 Texas Instruments, Incorporated. *
* All Rights Reserved. *
* ========================================================================= *
.global _DSP_fir_r4
* ========================================================================= *
* End of file: dsp_fir_r4.h62 *
* ------------------------------------------------------------------------- *
* Copyright (c) 2002 Texas Instruments, Incorporated. *
* All Rights Reserved. *
* ========================================================================= *