tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_iir_lattice_init_f32.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_iir_lattice_init_f32.c
   9 *
  10 * Description:  Floating-point IIR lattice 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 IIR_Lattice
  49  * @{
  50  */
  51
  52 /**
  53  * @brief Initialization function for the floating-point IIR lattice filter.
  54  * @param[in] *S points to an instance of the floating-point IIR lattice structure.
  55  * @param[in] numStages number of stages in the filter.
  56  * @param[in] *pkCoeffs points to the reflection coefficient buffer.  The array is of length numStages.
  57  * @param[in] *pvCoeffs points to the ladder coefficient buffer.  The array is of length numStages+1.
  58  * @param[in] *pState points to the state buffer.  The array is of length numStages+blockSize.
  59  * @param[in] blockSize number of samples to process.
  60  * @return none.
  61  */
  62
  63 void arm_iir_lattice_init_f32(
  64   arm_iir_lattice_instance_f32 * S,
  65   uint16_t numStages,
  66   float32_t * pkCoeffs,
  67   float32_t * pvCoeffs,
  68   float32_t * pState,
  69   uint32_t blockSize)
  70 {
  71   /* Assign filter taps */
  72   S->numStages = numStages;
  73
  74   /* Assign reflection coefficient pointer */
  75   S->pkCoeffs = pkCoeffs;
  76
  77   /* Assign ladder coefficient pointer */
  78   S->pvCoeffs = pvCoeffs;
  79
  80   /* Clear state buffer and size is always blockSize + numStages */
  81   memset(pState, 0, (numStages + blockSize) * sizeof(float32_t));
  82
  83   /* Assign state pointer */
  84   S->pState = pState;
  85
  86
  87 }
  88
  89   /**
  90    * @} end of IIR_Lattice group
  91    */