arm_fir_sparse_init_q7.c

00001 /* ----------------------------------------------------------------------    
00002 * Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
00003 *    
00004 * $Date:        19. March 2015
00005 * $Revision:    V.1.4.5
00006 *    
00007 * Project:      CMSIS DSP Library    
00008 * Title:        arm_fir_sparse_init_q7.c    
00009 *    
00010 * Description:  Q7 sparse FIR filter initialization function.   
00011 *    
00012 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
00013 *  
00014 * Redistribution and use in source and binary forms, with or without 
00015 * modification, are permitted provided that the following conditions
00016 * are met:
00017 *   - Redistributions of source code must retain the above copyright
00018 *     notice, this list of conditions and the following disclaimer.
00019 *   - Redistributions in binary form must reproduce the above copyright
00020 *     notice, this list of conditions and the following disclaimer in
00021 *     the documentation and/or other materials provided with the 
00022 *     distribution.
00023 *   - Neither the name of ARM LIMITED nor the names of its contributors
00024 *     may be used to endorse or promote products derived from this
00025 *     software without specific prior written permission.
00026 *
00027 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00028 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00029 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
00030 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
00031 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
00032 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
00033 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
00034 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
00035 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00036 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
00037 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
00038 * POSSIBILITY OF SUCH DAMAGE. 
00039 * ---------------------------------------------------------------------------*/
00040 
00041 #include "arm_math.h"
00042 
00043 /**    
00044  * @ingroup groupFilters    
00045  */
00046 
00047 /**    
00048  * @addtogroup FIR_Sparse    
00049  * @{    
00050  */
00051 
00052 /**   
00053  * @brief  Initialization function for the Q7 sparse FIR filter.   
00054  * @param[in,out] *S         points to an instance of the Q7 sparse FIR structure.   
00055  * @param[in]     numTaps    number of nonzero coefficients in the filter.   
00056  * @param[in]     *pCoeffs   points to the array of filter coefficients.   
00057  * @param[in]     *pState    points to the state buffer.   
00058  * @param[in]     *pTapDelay points to the array of offset times.   
00059  * @param[in]     maxDelay   maximum offset time supported.   
00060  * @param[in]     blockSize  number of samples that will be processed per block.   
00061  * @return none   
00062  *    
00063  * <b>Description:</b>    
00064  * \par    
00065  * <code>pCoeffs</code> holds the filter coefficients and has length <code>numTaps</code>.    
00066  * <code>pState</code> holds the filter's state variables and must be of length    
00067  * <code>maxDelay + blockSize</code>, where <code>maxDelay</code>    
00068  * is the maximum number of delay line values.    
00069  * <code>blockSize</code> is the    
00070  * number of samples processed by the <code>arm_fir_sparse_q7()</code> function.    
00071  */
00072 
00073 void arm_fir_sparse_init_q7(
00074   arm_fir_sparse_instance_q7 * S,
00075   uint16_t numTaps,
00076   q7_t * pCoeffs,
00077   q7_t * pState,
00078   int32_t * pTapDelay,
00079   uint16_t maxDelay,
00080   uint32_t blockSize)
00081 {
00082   /* Assign filter taps */
00083   S->numTaps = numTaps;
00084 
00085   /* Assign coefficient pointer */
00086   S->pCoeffs = pCoeffs;
00087 
00088   /* Assign TapDelay pointer */
00089   S->pTapDelay = pTapDelay;
00090 
00091   /* Assign MaxDelay */
00092   S->maxDelay = maxDelay;
00093 
00094   /* reset the stateIndex to 0 */
00095   S->stateIndex = 0u;
00096 
00097   /* Clear state buffer and size is always maxDelay + blockSize */
00098   memset(pState, 0, (maxDelay + blockSize) * sizeof(q7_t));
00099 
00100   /* Assign state pointer */
00101   S->pState = pState;
00102 
00103 }
00104 
00105 /**    
00106  * @} end of FIR_Sparse group    
00107  */