CMSIS DSP library

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cmsis_dsp/FilteringFunctions/arm_fir_sparse_init_q31.c

Committer:
emilmont
Date:
2012-11-28
Revision:
1:fdd22bb7aa52
Child:
2:da51fb522205

File content as of revision 1:fdd22bb7aa52:

/* ----------------------------------------------------------------------    
* Copyright (C) 2010 ARM Limited. All rights reserved.    
*    
* $Date:        15. February 2012  
* $Revision:     V1.1.0  
*    
* Project:         CMSIS DSP Library    
* Title:        arm_fir_sparse_init_q31.c    
*    
* Description:    Q31 sparse FIR filter initialization function.   
*    
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*  
* Version 1.1.0 2012/02/15 
*    Updated with more optimizations, bug fixes and minor API changes.  
*   
* Version 1.0.10 2011/7/15  
*    Big Endian support added and Merged M0 and M3/M4 Source code.   
*    
* 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"

/**    
 * @ingroup groupFilters    
 */

/**    
 * @addtogroup FIR_Sparse    
 * @{    
 */

/**   
 * @brief  Initialization function for the Q31 sparse FIR filter.   
 * @param[in,out] *S         points to an instance of the Q31 sparse FIR structure.   
 * @param[in]     numTaps    number of nonzero coefficients in the filter.   
 * @param[in]     *pCoeffs   points to the array of filter coefficients.   
 * @param[in]     *pState    points to the state buffer.   
 * @param[in]     *pTapDelay points to the array of offset times.   
 * @param[in]     maxDelay   maximum offset time supported.   
 * @param[in]     blockSize  number of samples that will be processed per block.   
 * @return none   
 *    
 * <b>Description:</b>    
 * \par    
 * <code>pCoeffs</code> holds the filter coefficients and has length <code>numTaps</code>.    
 * <code>pState</code> holds the filter's state variables and must be of length    
 * <code>maxDelay + blockSize</code>, where <code>maxDelay</code>    
 * is the maximum number of delay line values.    
 * <code>blockSize</code> is the number of words processed by <code>arm_fir_sparse_q31()</code> function.    
 */

void arm_fir_sparse_init_q31(
  arm_fir_sparse_instance_q31 * S,
  uint16_t numTaps,
  q31_t * pCoeffs,
  q31_t * pState,
  int32_t * pTapDelay,
  uint16_t maxDelay,
  uint32_t blockSize)
{
  /* Assign filter taps */
  S->numTaps = numTaps;

  /* Assign coefficient pointer */
  S->pCoeffs = pCoeffs;

  /* Assign TapDelay pointer */
  S->pTapDelay = pTapDelay;

  /* Assign MaxDelay */
  S->maxDelay = maxDelay;

  /* reset the stateIndex to 0 */
  S->stateIndex = 0u;

  /* Clear state buffer and size is always maxDelay + blockSize */
  memset(pState, 0, (maxDelay + blockSize) * sizeof(q31_t));

  /* Assign state pointer */
  S->pState = pState;

}

/**    
 * @} end of FIR_Sparse group    
 */