;* ======================================================================== *;
;* TEXAS INSTRUMENTS, INC. *;
;* *;
;* DSPLIB DSP Signal Processing Library *;
;* *;
;* Release: Version 1.02 *;
;* CVS Revision: 1.4 Fri Mar 22 01:54:04 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_minerror *
* *
* REVISION DATE *
* 08-Mar-2002 *
* *
* USAGE *
* This routine is C-callable and can be called as: *
* *
* int DSP_minerror *
* ( *
* const short *restrict GSP0_TABLE, *
* short *restrict errCoefs, *
* int *restrict max_index *
* ); *
* *
* GSP0_TABLE[256*9] : Pointer to GSP0 terms array. *
* Must be word aligned. *
* errCoefs[9] : Array of error coefficients. *
* Must be word aligned. *
* max_index : Index to GSP0_TABLE[max_index], the first *
* element of the 9-element vector that resulted *
* in the maximum dot product. *
* return int : Maximum dot product result. *
* *
* DESCRIPTION *
* Performs a dot product on 256 pairs of 9 element vectors and *
* searches for the pair of vectors which produces the maximum dot *
* product result. This is a large part of the VSELP vocoder codebook *
* search. *
* *
* C CODE *
* This is the C equivalent of the assembly code without restrictions *
* Note that the assembly code is hand optimized and restrictions may *
* apply. *
* *
* int DSP_minerror *
* ( *
* const short *restrict GSP0_TABLE, *
* short *restrict errCoefs, *
* int *restrict max_index *
* ) *
* { *
* int val, maxVal = -50; *
* int i, j; *
* *
* for (i = 0; i < GSP0_NUM; i++) *
* { *
* for (val = 0, j = 0; j < GSP0_TERMS; j++) *
* val += GSP0_TABLE[i*GSP0_TERMS+j] * errCoefs[j]; *
* *
* if (val > maxVal) *
* { *
* maxVal = val; *
* *max_index = i*GSP0_TERMS; *
* } *
* } *
* *
* return (maxVal); *
* } *
* *
* TECHNIQUES *
* Inner loop is completely unrolled. *
* Word-wide loads are used to read in GSP0_TABLE and errCoefs. *
* *
* ASSUMPTIONS *
* Arrays GSP0_TABLE[] and errCoefs[] must be word aligned. *
* *
* MEMORY NOTE *
* Align GSP0_TABLE[] and errCoefs[] at different memory banks to *
* avoid 4 bank conflicts. *
* *
* NOTES *
* This code is LITTLE ENDIAN. *
* This code is interrupt-tolerant but not interruptible. *
* *
* CYCLES *
* 1189 *
* *
* CODESIZE *
* 576 bytes *
* *
* ------------------------------------------------------------------------- *
* Copyright (c) 2002 Texas Instruments, Incorporated. *
* All Rights Reserved. *
* ========================================================================= *
.global _DSP_minerror
* ========================================================================= *
* End of file: dsp_minerror.h62 *
* ------------------------------------------------------------------------- *
* Copyright (c) 2002 Texas Instruments, Incorporated. *
* All Rights Reserved. *
* ========================================================================= *