File content as of revision 2:da51fb522205:

/* ----------------------------------------------------------------------    
* Copyright (C) 2010 ARM Limited. All rights reserved.    
*    
* $Date:        15. February 2012  
* $Revision: 	V1.1.0  
*    
* Project: 	    CMSIS DSP Library    
* Title:        arm_fir_init_q7.c    
*    
* Description:  Q7 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 0.0.5  2010/04/26     
* 	 incorporated review comments and updated with latest CMSIS layer    
*    
* Version 0.0.3  2010/03/10     
*    Initial version    
* ------------------------------------------------------------------- */

#include "arm_math.h"

/**    
 * @ingroup groupFilters    
 */

/**    
 * @addtogroup FIR    
 * @{    
 */
/**    
 * @param[in,out] *S points to an instance of the Q7 FIR filter structure.    
 * @param[in] 	  numTaps  Number of filter coefficients in the filter.    
 * @param[in] 	  *pCoeffs points to the filter coefficients buffer.    
 * @param[in]     *pState points to the state buffer.    
 * @param[in]     blockSize number of samples that are processed per call.    
 * @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>    
 * \par    
 * <code>pState</code> points to the array of state variables.    
 * <code>pState</code> is 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_fir_q7()</code>.    
 */

void arm_fir_init_q7(
  arm_fir_instance_q7 * S,
  uint16_t numTaps,
  q7_t * pCoeffs,
  q7_t * pState,
  uint32_t blockSize)
{

  /* Assign filter taps */
  S->numTaps = numTaps;

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

  /* Clear the state buffer.  The size is always (blockSize + numTaps - 1) */
  memset(pState, 0, (numTaps + (blockSize - 1u)) * sizeof(q7_t));

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

}

/**    
 * @} end of FIR group    
 */