/* ---------------------------------------------------------------------- * Copyright (C) 2010-2014 ARM Limited. All rights reserved. * * $Date: 19. March 2015 * $Revision: V.1.4.5 * * Project: CMSIS DSP Library * Title: arm_fir_init_q31.c * * Description: Q31 FIR filter initialization function. * * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * - Neither the name of ARM LIMITED nor the names of its contributors * may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * -------------------------------------------------------------------- */ #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. * * Description: * \par * pCoeffs points to the array of filter coefficients stored in time reversed order: *
    
 *    {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]}    
 * 
* \par * pState points to the array of state variables. * pState is of length numTaps+blockSize-1 samples, where blockSize is the number of input samples processed by each call to arm_fir_q31(). */ 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 */