Joep D / CMSIS_DSP_5

The CMSIS DSP 5 library

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functions/FilteringFunctions/arm_fir_init_q31.c@3:4098b9d3d571, 2018-06-21 (annotated)

Committer:
xorjoep
Date:
Thu Jun 21 11:56:27 2018 +0000
Revision:
3:4098b9d3d571
Parent:
1:24714b45cd1b 
headers is a folder not a library

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xorjoep 1:24714b45cd1b 1 /* ----------------------------------------------------------------------
xorjoep 1:24714b45cd1b 2 * Project: CMSIS DSP Library
xorjoep 1:24714b45cd1b 3 * Title: arm_fir_init_q31.c
xorjoep 1:24714b45cd1b 4 * Description: Q31 FIR filter initialization function.
xorjoep 1:24714b45cd1b 5 *
xorjoep 1:24714b45cd1b 6 * $Date: 27. January 2017
xorjoep 1:24714b45cd1b 7 * $Revision: V.1.5.1
xorjoep 1:24714b45cd1b 8 *
xorjoep 1:24714b45cd1b 9 * Target Processor: Cortex-M cores
xorjoep 1:24714b45cd1b 10 * -------------------------------------------------------------------- */
xorjoep 1:24714b45cd1b 11 /*
xorjoep 1:24714b45cd1b 12 * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
xorjoep 1:24714b45cd1b 13 *
xorjoep 1:24714b45cd1b 14 * SPDX-License-Identifier: Apache-2.0
xorjoep 1:24714b45cd1b 15 *
xorjoep 1:24714b45cd1b 16 * Licensed under the Apache License, Version 2.0 (the License); you may
xorjoep 1:24714b45cd1b 17 * not use this file except in compliance with the License.
xorjoep 1:24714b45cd1b 18 * You may obtain a copy of the License at
xorjoep 1:24714b45cd1b 19 *
xorjoep 1:24714b45cd1b 20 * www.apache.org/licenses/LICENSE-2.0
xorjoep 1:24714b45cd1b 21 *
xorjoep 1:24714b45cd1b 22 * Unless required by applicable law or agreed to in writing, software
xorjoep 1:24714b45cd1b 23 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
xorjoep 1:24714b45cd1b 24 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
xorjoep 1:24714b45cd1b 25 * See the License for the specific language governing permissions and
xorjoep 1:24714b45cd1b 26 * limitations under the License.
xorjoep 1:24714b45cd1b 27 */
xorjoep 1:24714b45cd1b 28
xorjoep 1:24714b45cd1b 29 #include "arm_math.h"
xorjoep 1:24714b45cd1b 30
xorjoep 1:24714b45cd1b 31 /**
xorjoep 1:24714b45cd1b 32 * @ingroup groupFilters
xorjoep 1:24714b45cd1b 33 */
xorjoep 1:24714b45cd1b 34
xorjoep 1:24714b45cd1b 35 /**
xorjoep 1:24714b45cd1b 36 * @addtogroup FIR
xorjoep 1:24714b45cd1b 37 * @{
xorjoep 1:24714b45cd1b 38 */
xorjoep 1:24714b45cd1b 39
xorjoep 1:24714b45cd1b 40 /**
xorjoep 1:24714b45cd1b 41 * @details
xorjoep 1:24714b45cd1b 42 *
xorjoep 1:24714b45cd1b 43 * @param[in,out] *S points to an instance of the Q31 FIR filter structure.
xorjoep 1:24714b45cd1b 44 * @param[in] numTaps Number of filter coefficients in the filter.
xorjoep 1:24714b45cd1b 45 * @param[in] *pCoeffs points to the filter coefficients buffer.
xorjoep 1:24714b45cd1b 46 * @param[in] *pState points to the state buffer.
xorjoep 1:24714b45cd1b 47 * @param[in] blockSize number of samples that are processed per call.
xorjoep 1:24714b45cd1b 48 * @return none.
xorjoep 1:24714b45cd1b 49 *
xorjoep 1:24714b45cd1b 50 * <b>Description:</b>
xorjoep 1:24714b45cd1b 51 * \par
xorjoep 1:24714b45cd1b 52 * <code>pCoeffs</code> points to the array of filter coefficients stored in time reversed order:
xorjoep 1:24714b45cd1b 53 * <pre>
xorjoep 1:24714b45cd1b 54 * {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]}
xorjoep 1:24714b45cd1b 55 * </pre>
xorjoep 1:24714b45cd1b 56 * \par
xorjoep 1:24714b45cd1b 57 * <code>pState</code> points to the array of state variables.
xorjoep 1:24714b45cd1b 58 * <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>.
xorjoep 1:24714b45cd1b 59 */
xorjoep 1:24714b45cd1b 60
xorjoep 1:24714b45cd1b 61 void arm_fir_init_q31(
xorjoep 1:24714b45cd1b 62 arm_fir_instance_q31 * S,
xorjoep 1:24714b45cd1b 63 uint16_t numTaps,
xorjoep 1:24714b45cd1b 64 q31_t * pCoeffs,
xorjoep 1:24714b45cd1b 65 q31_t * pState,
xorjoep 1:24714b45cd1b 66 uint32_t blockSize)
xorjoep 1:24714b45cd1b 67 {
xorjoep 1:24714b45cd1b 68 /* Assign filter taps */
xorjoep 1:24714b45cd1b 69 S->numTaps = numTaps;
xorjoep 1:24714b45cd1b 70
xorjoep 1:24714b45cd1b 71 /* Assign coefficient pointer */
xorjoep 1:24714b45cd1b 72 S->pCoeffs = pCoeffs;
xorjoep 1:24714b45cd1b 73
xorjoep 1:24714b45cd1b 74 /* Clear state buffer and state array size is (blockSize + numTaps - 1) */
xorjoep 1:24714b45cd1b 75 memset(pState, 0, (blockSize + ((uint32_t) numTaps - 1U)) * sizeof(q31_t));
xorjoep 1:24714b45cd1b 76
xorjoep 1:24714b45cd1b 77 /* Assign state pointer */
xorjoep 1:24714b45cd1b 78 S->pState = pState;
xorjoep 1:24714b45cd1b 79
xorjoep 1:24714b45cd1b 80 }
xorjoep 1:24714b45cd1b 81
xorjoep 1:24714b45cd1b 82 /**
xorjoep 1:24714b45cd1b 83 * @} end of FIR group
xorjoep 1:24714b45cd1b 84 */