/* ----------------------------------------------------------------------  
* Copyright (C) 2010 ARM Limited. All rights reserved.  
*  
* $Date:        29. November 2010  
* $Revision: 	V1.0.3  
*  
* Project: 	    CMSIS DSP Library  
* Title:	    arm_fir_init_q31.c  
*  
* Description:	Q31 FIR filter 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 0.0.5  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  
 * @{  
 */ 
 
/**  
 * @details  
 *  
 * @param[in,out] *S points to an instance of the Q31 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_q31()</code>.  
 */ 
 
void arm_fir_init_q31( 
  arm_fir_instance_q31 * S, 
  uint16_t numTaps, 
  q31_t * pCoeffs, 
  q31_t * pState, 
  uint32_t blockSize) 
{ 
  /* Assign filter taps */ 
  S->numTaps = numTaps; 
 
  /* Assign coefficient pointer */ 
  S->pCoeffs = pCoeffs; 
 
  /* Clear state buffer and state array size is (blockSize + numTaps - 1) */ 
  memset(pState, 0, (blockSize + ((uint32_t) numTaps - 1u)) * sizeof(q31_t)); 
 
  /* Assign state pointer */ 
  S->pState = pState; 
 
} 
 
/**  
 * @} end of FIR group  
 */ 
