text: /*-----------------------------------------------------------------------------    
  * Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
  *    
  * $Date:        19. March 2015
  * $Revision: 	V.1.4.5
  *    
  * Project: 	    CMSIS DSP Library    
  * Title:        arm_biquad_cascade_df2T_init_f64.c    
  *    
  * Description:  Initialization function for the floating-point transposed   
  *               direct form II Biquad cascade filter.   
  *    
  * 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"
  
  /**    
   * @ingroup groupFilters    
   */
  
  /**    
   * @addtogroup BiquadCascadeDF2T    
   * @{    
   */
  
  /**   
   * @brief  Initialization function for the floating-point transposed direct form II Biquad cascade filter.   
   * @param[in,out] *S           points to an instance of the filter data structure.   
   * @param[in]     numStages    number of 2nd order stages in the filter.   
   * @param[in]     *pCoeffs     points to the filter coefficients.   
   * @param[in]     *pState      points to the state buffer.   
   * @return        none   
   *    
   * <b>Coefficient and State Ordering:</b>    
   * \par    
   * The coefficients are stored in the array <code>pCoeffs</code> in the following order:    
   * <pre>    
   *     {b10, b11, b12, a11, a12, b20, b21, b22, a21, a22, ...}    
   * </pre>    
   *    
   * \par    
   * where <code>b1x</code> and <code>a1x</code> are the coefficients for the first stage,    
   * <code>b2x</code> and <code>a2x</code> are the coefficients for the second stage,    
   * and so on.  The <code>pCoeffs</code> array contains a total of <code>5*numStages</code> values.    
   *    
   * \par    
   * The <code>pState</code> is a pointer to state array.    
   * Each Biquad stage has 2 state variables <code>d1,</code> and <code>d2</code>.    
   * The 2 state variables for stage 1 are first, then the 2 state variables for stage 2, and so on.    
   * The state array has a total length of <code>2*numStages</code> values.    
   * The state variables are updated after each block of data is processed; the coefficients are untouched.    
   */
  
  void arm_biquad_cascade_df2T_init_f64(
    arm_biquad_cascade_df2T_instance_f64 * S,
    uint8_t numStages,
    float64_t * pCoeffs,
    float64_t * pState)
  {
    /* Assign filter stages */
    S->numStages = numStages;
  
    /* Assign coefficient pointer */
    S->pCoeffs = pCoeffs;
  
    /* Clear state buffer and size is always 2 * numStages */
    memset(pState, 0, (2u * (uint32_t) numStages) * sizeof(float64_t));
  
    /* Assign state pointer */
    S->pState = pState;
  }
  
  /**    
   * @} end of BiquadCascadeDF2T group    
   */
  