dsp_q15tofl.h64

来自「dm642函数库」· H64 代码 · 共 101 行

;* ======================================================================== *;
;*  TEXAS INSTRUMENTS, INC.                                                 *;
;*                                                                          *;
;*  DSPLIB  DSP Signal Processing Library                                   *;
;*                                                                          *;
;*      Release:        Revision 1.04b                                      *;
;*      CVS Revision:   1.6     Sun Sep 29 03:32:28 2002 (UTC)              *;
;*      Snapshot date:  23-Oct-2003                                         *;
;*                                                                          *;
;*  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) 2003 Texas Instruments, Incorporated.             *;
;*                          All Rights Reserved.                            *;
;* ======================================================================== *;
;* ======================================================================== *;
;*  Assembler compatibility shim for assembling 4.30 and later code on      *;
;*  tools prior to 4.30.                                                    *;
;* ======================================================================== *;
;* ======================================================================== *;
;*  End of assembler compatibility shim.                                    *;
;* ======================================================================== *;
* ========================================================================= *
*                                                                           *
*   TEXAS INSTRUMENTS, INC.                                                 *
*                                                                           *
*   NAME                                                                    *
*       DSP_q15tofl -- Q.15 to IEEE float conversion                        *
*                                                                           *
*   REVISION DATE                                                           *
*       17-Jul-2001                                                         *
*                                                                           *
*   USAGE                                                                   *
*       This routine is C-callable and can be called as:                    *
*                                                                           *
*           void DSP_q15tofl (short *x, float *r, int nx);                  *
*                                                                           *
*           x[nx]  ---  Pointer to Q15 input vector of size nx              *
*           r[nx]  ---  Pointer to floating-point output data vector        *
*                       of size nx containing the floating-point equivalent *
*                       of vector input                                     *
*           nx     ---  length of input and output data vectors             *
*                                                                           *
*                                                                           *
*   DESCRIPTION                                                             *
*       Converts the Q15 stored in vector input to IEEE floating point      *
*       numbers stored in vector output.                                    *
*                                                                           *
*       void DSP_q15tofl (short *x, float *r, int nx)                       *
*       {                                                                   *
*        int i;                                                             *
*                                                                           *
*        for (i=0;i<nx;i++)                                                 *
*             r[i]=(float)x[i]/0x8000;                                      *
*       }                                                                   *
*                                                                           *
*       The above C code is a general implementation without                *
*       restrictions.  The assembly code may have some restrictions, as     *
*       noted below.                                                        *
*                                                                           *
*   TECHNIQUES                                                              *
*       unrolled loop 2x                                                    *
*       split live-too-longs B_input_1 and B_input_2                        *
*       collapsed 2 prolog and epilog stages                                *
*                                                                           *
*   ASSUMPTIONS                                                             *
*       nx >=2 and multiple of 2                                            *
*                                                                           *
*   MEMORY NOTE                                                             *
*       no bank conflicts occur ever                                        *
*                                                                           *
*   NOTES                                                                   *
*       this routine is interrupt-tolerant but not interruptible            *
*       this routine is ENDIAN NEUTRAL                                      *
*                                                                           *
*   CYCLES                                                                  *
*       14 + 2 * nx                                                         *
*                                                                           *
*   CODESIZE                                                                *
*       184 bytes                                                           *
* ------------------------------------------------------------------------- *
*             Copyright (c) 2003 Texas Instruments, Incorporated.           *
*                            All Rights Reserved.                           *
* ========================================================================= *

        .global _DSP_q15tofl

* ========================================================================= *
*   End of file:  dsp_q15tofl.h64                                           *
* ------------------------------------------------------------------------- *
*             Copyright (c) 2003 Texas Instruments, Incorporated.           *
*                            All Rights Reserved.                           *
* ========================================================================= *