text: /*-----------------------------------------------------------------------------    
  * Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
  *    
  * $Date:        12. March 2014
  * $Revision: 	V1.4.4
  *    
  * Project: 	    CMSIS DSP Library    
  * Title:        arm_lms_norm_init_q15.c    
  *    
  * Description:  Q15 NLMS initialization function.    
  *    
  * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
  *  
  * Redistribution and use in source and binary forms, with or without 
  * modification, are permitted provided that the following conditions
  * are met:
  *   - Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  *   - Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in
  *     the documentation and/or other materials provided with the 
  *     distribution.
  *   - Neither the name of ARM LIMITED nor the names of its contributors
  *     may be used to endorse or promote products derived from this
  *     software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.   
  * ---------------------------------------------------------------------------*/
  
  #include "arm_math.h"
  #include "arm_common_tables.h"
  
  /**    
   * @addtogroup LMS_NORM    
   * @{    
   */
  
    /**    
     * @brief Initialization function for Q15 normalized LMS filter.    
     * @param[in] *S points to an instance of the Q15 normalized LMS filter structure.    
     * @param[in] numTaps  number of filter coefficients.    
     * @param[in] *pCoeffs points to coefficient buffer.    
     * @param[in] *pState points to state buffer.    
     * @param[in] mu step size that controls filter coefficient updates.    
     * @param[in] blockSize number of samples to process.    
     * @param[in] postShift bit shift applied to coefficients.    
     * @return none.    
   *    
   * <b>Description:</b>    
   * \par    
   * <code>pCoeffs</code> points to the array of filter coefficients stored in time reversed order:    
   * <pre>    
   *    {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]}    
   * </pre>    
   * The initial filter coefficients serve as a starting point for the adaptive filter.    
   * <code>pState</code> points to the array of state variables and size of array is    
   * <code>numTaps+blockSize-1</code> samples, where <code>blockSize</code> is the number of input samples processed    
   * by each call to <code>arm_lms_norm_q15()</code>.    
   */
  
  void arm_lms_norm_init_q15(
    arm_lms_norm_instance_q15 * S,
    uint16_t numTaps,
    q15_t * pCoeffs,
    q15_t * pState,
    q15_t mu,
    uint32_t blockSize,
    uint8_t postShift)
  {
    /* Assign filter taps */
    S->numTaps = numTaps;
  
    /* Assign coefficient pointer */
    S->pCoeffs = pCoeffs;
  
    /* Clear state buffer and size is always blockSize + numTaps - 1 */
    memset(pState, 0, (numTaps + (blockSize - 1u)) * sizeof(q15_t));
  
    /* Assign post Shift value applied to coefficients */
    S->postShift = postShift;
  
    /* Assign state pointer */
    S->pState = pState;
  
    /* Assign Step size value */
    S->mu = mu;
  
    /* Initialize reciprocal pointer table */
    S->recipTable = (q15_t *) armRecipTableQ15;
  
    /* Initialise Energy to zero */
    S->energy = 0;
  
    /* Initialise x0 to zero */
    S->x0 = 0;
  
  }
  
  /**    
   * @} end of LMS_NORM group    
   */
  