- Main Page
- Modules
- Data Structures
- Files
- Examples

- File List
- Globals

# arm_q15_to_float.c

Go to the documentation of this file.

    00001 /* ----------------------------------------------------------------------------
    00002 * Copyright (C) 2010 ARM Limited. All rights reserved.
    00003 *
    00004 * $Date:        29. November 2010
    00005 * $Revision:    V1.0.3
    00006 *
    00007 * Project:      CMSIS DSP Library
    00008 * Title:        arm_q15_to_float.c
    00009 *
    00010 * Description:  Processing function for the Conversion from Q15 to float
    00011 *
    00012 * Target Processor: Cortex-M4/Cortex-M3
    00013 *
    00014 * Version 1.0.3 2010/11/29
    00015 *    Re-organized the CMSIS folders and updated documentation.
    00016 *
    00017 * Version 1.0.2 2010/11/11
    00018 *    Documentation updated.
    00019 *
    00020 * Version 1.0.1 2010/10/05
    00021 *    Production release and review comments incorporated.
    00022 *
    00023 * Version 1.0.0 2010/09/20
    00024 *    Production release and review comments incorporated.
    00025 * ---------------------------------------------------------------------------- */
    00026
    00027 #include "arm_math.h"
    00028
    00063 void arm_q15_to_float(
    00064   q15_t * pSrc,
    00065   float32_t * pDst,
    00066   uint32_t blockSize)
    00067 {
    00068   q15_t *pIn = pSrc;                             /* Src pointer */
    00069   uint32_t blkCnt;                               /* loop counter */
    00070
    00071
    00072   /*loop Unrolling */
    00073   blkCnt = blockSize >> 2u;
    00074
    00075   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
    00076    ** a second loop below computes the remaining 1 to 3 samples. */
    00077   while(blkCnt > 0u)
    00078   {
    00079     /* C = (float32_t) A / 32768 */
    00080     /* convert from q15 to float and then store the results in the destination buffer */
    00081     *pDst++ = ((float32_t) * pIn++ / 32768.0f);
    00082     *pDst++ = ((float32_t) * pIn++ / 32768.0f);
    00083     *pDst++ = ((float32_t) * pIn++ / 32768.0f);
    00084     *pDst++ = ((float32_t) * pIn++ / 32768.0f);
    00085
    00086     /* Decrement the loop counter */
    00087     blkCnt--;
    00088   }
    00089
    00090   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
    00091    ** No loop unrolling is used. */
    00092   blkCnt = blockSize % 0x4u;
    00093
    00094   while(blkCnt > 0u)
    00095   {
    00096     /* C = (float32_t) A / 32768 */
    00097     /* convert from q15 to float and then store the results in the destination buffer */
    00098     *pDst++ = ((float32_t) * pIn++ / 32768.0f);
    00099
    00100     /* Decrement the loop counter */
    00101     blkCnt--;
    00102   }
    00103 }
    00104

All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Defines