/*-----------------------------------------------------------------------------  
* Copyright (C) 2010 ARM Limited. All rights reserved.  
*  
* $Date:        29. November 2010  
* $Revision: 	V1.0.3  
*  
* Project: 	    CMSIS DSP Library  
* Title:        arm_lms_norm_init_q31.c  
*  
* Description:  Q31 NLMS initialization function.  
*  
* Target Processor: Cortex-M4/Cortex-M3
*  
* Version 1.0.3 2010/11/29 
*    Re-organized the CMSIS folders and updated documentation.  
*   
* Version 1.0.2 2010/11/11  
*    Documentation updated.   
*  
* Version 1.0.1 2010/10/05   
*    Production release and review comments incorporated.  
*  
* Version 1.0.0 2010/09/20   
*    Production release and review comments incorporated  
*  
* Version 0.0.7  2010/06/10   
*    Misra-C changes done  
* ---------------------------------------------------------------------------*/ 
 
#include "arm_math.h" 
#include "arm_common_tables.h" 
 
/**  
 * @addtogroup LMS_NORM  
 * @{  
 */ 
 
  /**  
   * @brief Initialization function for Q31 normalized LMS filter.  
   * @param[in] *S points to an instance of the Q31 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 an array of length <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_q31()</code>.  
 */ 
 
void arm_lms_norm_init_q31( 
  arm_lms_norm_instance_q31 * S, 
  uint16_t numTaps, 
  q31_t * pCoeffs, 
  q31_t * pState, 
  q31_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(q31_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 = armRecipTableQ31; 
 
  /* Initialise Energy to zero */ 
  S->energy = 0; 
 
  /* Initialise x0 to zero */ 
  S->x0 = 0; 
 
} 
 
/**  
 * @} end of LMS_NORM group  
 */