arm_fir_sparse_init_q15.c

00001 /* ----------------------------------------------------------------------  
00002 * Copyright (C) 2010 ARM Limited. All rights reserved.  
00003 *  
00004 * $Date:        29. November 2010  
00005 * $Revision:    V1.0.3  
00006 *  
00007 * Project:      CMSIS DSP Library  
00008 * Title:        arm_fir_sparse_init_q15.c  
00009 *  
00010 * Description:  Q15 sparse FIR filter initialization function. 
00011 *  
00012 * Target Processor: Cortex-M4/Cortex-M3
00013 *  
00014 * Version 1.0.3 2010/11/29 
00015 *    Re-organized the CMSIS folders and updated documentation.  
00016 *   
00017 * Version 1.0.2 2010/11/11  
00018 *    Documentation updated.   
00019 *  
00020 * Version 1.0.1 2010/10/05   
00021 *    Production release and review comments incorporated.  
00022 *  
00023 * Version 1.0.0 2010/09/20   
00024 *    Production release and review comments incorporated  
00025 *  
00026 * Version 0.0.7  2010/06/10   
00027 *    Misra-C changes done  
00028 * ---------------------------------------------------------------------------*/ 
00029  
00030 #include "arm_math.h" 
00031  
00032 /**  
00033  * @ingroup groupFilters  
00034  */ 
00035  
00036 /**  
00037  * @addtogroup FIR_Sparse  
00038  * @{  
00039  */ 
00040  
00041 /** 
00042  * @brief  Initialization function for the Q15 sparse FIR filter. 
00043  * @param[in,out] *S         points to an instance of the Q15 sparse FIR structure. 
00044  * @param[in]     numTaps    number of nonzero coefficients in the filter. 
00045  * @param[in]     *pCoeffs   points to the array of filter coefficients. 
00046  * @param[in]     *pState    points to the state buffer. 
00047  * @param[in]     *pTapDelay points to the array of offset times. 
00048  * @param[in]     maxDelay   maximum offset time supported. 
00049  * @param[in]     blockSize  number of samples that will be processed per block. 
00050  * @return none 
00051  *  
00052  * <b>Description:</b>  
00053  * \par  
00054  * <code>pCoeffs</code> holds the filter coefficients and has length <code>numTaps</code>.  
00055  * <code>pState</code> holds the filter's state variables and must be of length  
00056  * <code>maxDelay + blockSize</code>, where <code>maxDelay</code>  
00057  * is the maximum number of delay line values.  
00058  * <code>blockSize</code> is the  
00059  * number of words processed by <code>arm_fir_sparse_q15()</code> function.  
00060  */ 
00061  
00062 void arm_fir_sparse_init_q15( 
00063   arm_fir_sparse_instance_q15 * S, 
00064   uint16_t numTaps, 
00065   q15_t * pCoeffs, 
00066   q15_t * pState, 
00067   int32_t * pTapDelay, 
00068   uint16_t maxDelay, 
00069   uint32_t blockSize) 
00070 { 
00071   /* Assign filter taps */ 
00072   S->numTaps = numTaps; 
00073  
00074   /* Assign coefficient pointer */ 
00075   S->pCoeffs = pCoeffs; 
00076  
00077   /* Assign TapDelay pointer */ 
00078   S->pTapDelay = pTapDelay; 
00079  
00080   /* Assign MaxDelay */ 
00081   S->maxDelay = maxDelay; 
00082  
00083   /* reset the stateIndex to 0 */ 
00084   S->stateIndex = 0u; 
00085  
00086   /* Clear state buffer and size is always maxDelay + blockSize */ 
00087   memset(pState, 0, (maxDelay + blockSize) * sizeof(q15_t)); 
00088  
00089   /* Assign state pointer */ 
00090   S->pState = pState; 
00091  
00092 } 
00093  
00094 /**  
00095  * @} end of FIR_Sparse group  
00096  */