tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_sparse_init_q31.c

   1 /* ----------------------------------------------------------------------
   2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
   3 *
   4 * $Date:        17. January 2013
   5 * $Revision:    V1.4.1
   6 *
   7 * Project:          CMSIS DSP Library
   8 * Title:        arm_fir_sparse_init_q31.c
   9 *
  10 * Description:  Q31 sparse FIR filter initialization function.
  11 *
  12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
  13 *
  14 * Redistribution and use in source and binary forms, with or without
  15 * modification, are permitted provided that the following conditions
  16 * are met:
  17 *   - Redistributions of source code must retain the above copyright
  18 *     notice, this list of conditions and the following disclaimer.
  19 *   - Redistributions in binary form must reproduce the above copyright
  20 *     notice, this list of conditions and the following disclaimer in
  21 *     the documentation and/or other materials provided with the
  22 *     distribution.
  23 *   - Neither the name of ARM LIMITED nor the names of its contributors
  24 *     may be used to endorse or promote products derived from this
  25 *     software without specific prior written permission.
  26 *
  27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  38 * POSSIBILITY OF SUCH DAMAGE.
  39 * ---------------------------------------------------------------------------*/
  40
  41 #include "arm_math.h"
  42
  43 /**
  44  * @ingroup groupFilters
  45  */
  46
  47 /**
  48  * @addtogroup FIR_Sparse
  49  * @{
  50  */
  51
  52 /**
  53  * @brief  Initialization function for the Q31 sparse FIR filter.
  54  * @param[in,out] *S         points to an instance of the Q31 sparse FIR structure.
  55  * @param[in]     numTaps    number of nonzero coefficients in the filter.
  56  * @param[in]     *pCoeffs   points to the array of filter coefficients.
  57  * @param[in]     *pState    points to the state buffer.
  58  * @param[in]     *pTapDelay points to the array of offset times.
  59  * @param[in]     maxDelay   maximum offset time supported.
  60  * @param[in]     blockSize  number of samples that will be processed per block.
  61  * @return none
  62  *
  63  * <b>Description:</b>
  64  * \par
  65  * <code>pCoeffs</code> holds the filter coefficients and has length <code>numTaps</code>.
  66  * <code>pState</code> holds the filter's state variables and must be of length
  67  * <code>maxDelay + blockSize</code>, where <code>maxDelay</code>
  68  * is the maximum number of delay line values.
  69  * <code>blockSize</code> is the number of words processed by <code>arm_fir_sparse_q31()</code> function.
  70  */
  71
  72 void arm_fir_sparse_init_q31(
  73   arm_fir_sparse_instance_q31 * S,
  74   uint16_t numTaps,
  75   q31_t * pCoeffs,
  76   q31_t * pState,
  77   int32_t * pTapDelay,
  78   uint16_t maxDelay,
  79   uint32_t blockSize)
  80 {
  81   /* Assign filter taps */
  82   S->numTaps = numTaps;
  83
  84   /* Assign coefficient pointer */
  85   S->pCoeffs = pCoeffs;
  86
  87   /* Assign TapDelay pointer */
  88   S->pTapDelay = pTapDelay;
  89
  90   /* Assign MaxDelay */
  91   S->maxDelay = maxDelay;
  92
  93   /* reset the stateIndex to 0 */
  94   S->stateIndex = 0u;
  95
  96   /* Clear state buffer and size is always maxDelay + blockSize */
  97   memset(pState, 0, (maxDelay + blockSize) * sizeof(q31_t));
  98
  99   /* Assign state pointer */
 100   S->pState = pState;
 101
 102 }
 103
 104 /**
 105  * @} end of FIR_Sparse group
 106  */