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CMSIS DSP library

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cmsis_dsp/FilteringFunctions/arm_fir_decimate_init_q31.c@5:3762170b6d4d, 2015-11-20 (annotated)

Committer:
mbed_official
Date:
Fri Nov 20 08:45:18 2015 +0000
Revision:
5:3762170b6d4d
Parent:
3:7a284390b0ce 
Synchronized with git revision 2eb940b9a73af188d3004a2575fdfbb05febe62b



Full URL: https://github.com/mbedmicro/mbed/commit/2eb940b9a73af188d3004a2575fdfbb05febe62b/



Added option to build rpc library. closes #1426

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 1:fdd22bb7aa52 1 /* ----------------------------------------------------------------------
mbed_official 5:3762170b6d4d 2 * Copyright (C) 2010-2014 ARM Limited. All rights reserved.
emilmont 1:fdd22bb7aa52 3 *
mbed_official 5:3762170b6d4d 4 * $Date: 19. March 2015
mbed_official 5:3762170b6d4d 5 * $Revision: V.1.4.5
emilmont 1:fdd22bb7aa52 6 *
emilmont 2:da51fb522205 7 * Project: CMSIS DSP Library
emilmont 1:fdd22bb7aa52 8 * Title: arm_fir_decimate_init_q31.c
emilmont 1:fdd22bb7aa52 9 *
emilmont 1:fdd22bb7aa52 10 * Description: Initialization function for Q31 FIR Decimation filter.
emilmont 1:fdd22bb7aa52 11 *
emilmont 1:fdd22bb7aa52 12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
emilmont 1:fdd22bb7aa52 13 *
mbed_official 3:7a284390b0ce 14 * Redistribution and use in source and binary forms, with or without
mbed_official 3:7a284390b0ce 15 * modification, are permitted provided that the following conditions
mbed_official 3:7a284390b0ce 16 * are met:
mbed_official 3:7a284390b0ce 17 * - Redistributions of source code must retain the above copyright
mbed_official 3:7a284390b0ce 18 * notice, this list of conditions and the following disclaimer.
mbed_official 3:7a284390b0ce 19 * - Redistributions in binary form must reproduce the above copyright
mbed_official 3:7a284390b0ce 20 * notice, this list of conditions and the following disclaimer in
mbed_official 3:7a284390b0ce 21 * the documentation and/or other materials provided with the
mbed_official 3:7a284390b0ce 22 * distribution.
mbed_official 3:7a284390b0ce 23 * - Neither the name of ARM LIMITED nor the names of its contributors
mbed_official 3:7a284390b0ce 24 * may be used to endorse or promote products derived from this
mbed_official 3:7a284390b0ce 25 * software without specific prior written permission.
mbed_official 3:7a284390b0ce 26 *
mbed_official 3:7a284390b0ce 27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
mbed_official 3:7a284390b0ce 28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
mbed_official 3:7a284390b0ce 29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
mbed_official 3:7a284390b0ce 30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
mbed_official 3:7a284390b0ce 31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
mbed_official 3:7a284390b0ce 32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
mbed_official 3:7a284390b0ce 33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
mbed_official 3:7a284390b0ce 34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
mbed_official 3:7a284390b0ce 35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
mbed_official 3:7a284390b0ce 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
mbed_official 3:7a284390b0ce 37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
mbed_official 3:7a284390b0ce 38 * POSSIBILITY OF SUCH DAMAGE.
emilmont 1:fdd22bb7aa52 39 * ------------------------------------------------------------------- */
emilmont 1:fdd22bb7aa52 40
emilmont 1:fdd22bb7aa52 41 #include "arm_math.h"
emilmont 1:fdd22bb7aa52 42
emilmont 1:fdd22bb7aa52 43 /**
emilmont 1:fdd22bb7aa52 44 * @ingroup groupFilters
emilmont 1:fdd22bb7aa52 45 */
emilmont 1:fdd22bb7aa52 46
emilmont 1:fdd22bb7aa52 47 /**
emilmont 1:fdd22bb7aa52 48 * @addtogroup FIR_decimate
emilmont 1:fdd22bb7aa52 49 * @{
emilmont 1:fdd22bb7aa52 50 */
emilmont 1:fdd22bb7aa52 51
emilmont 1:fdd22bb7aa52 52 /**
emilmont 1:fdd22bb7aa52 53 * @brief Initialization function for the Q31 FIR decimator.
emilmont 1:fdd22bb7aa52 54 * @param[in,out] *S points to an instance of the Q31 FIR decimator structure.
emilmont 1:fdd22bb7aa52 55 * @param[in] numTaps number of coefficients in the filter.
emilmont 1:fdd22bb7aa52 56 * @param[in] M decimation factor.
emilmont 1:fdd22bb7aa52 57 * @param[in] *pCoeffs points to the filter coefficients.
emilmont 1:fdd22bb7aa52 58 * @param[in] *pState points to the state buffer.
emilmont 1:fdd22bb7aa52 59 * @param[in] blockSize number of input samples to process per call.
emilmont 1:fdd22bb7aa52 60 * @return The function returns ARM_MATH_SUCCESS if initialization was successful or ARM_MATH_LENGTH_ERROR if
emilmont 1:fdd22bb7aa52 61 * <code>blockSize</code> is not a multiple of <code>M</code>.
emilmont 1:fdd22bb7aa52 62 *
emilmont 1:fdd22bb7aa52 63 * <b>Description:</b>
emilmont 1:fdd22bb7aa52 64 * \par
emilmont 1:fdd22bb7aa52 65 * <code>pCoeffs</code> points to the array of filter coefficients stored in time reversed order:
emilmont 1:fdd22bb7aa52 66 * <pre>
emilmont 1:fdd22bb7aa52 67 * {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]}
emilmont 1:fdd22bb7aa52 68 * </pre>
emilmont 1:fdd22bb7aa52 69 * \par
emilmont 1:fdd22bb7aa52 70 * <code>pState</code> points to the array of state variables.
emilmont 1:fdd22bb7aa52 71 * <code>pState</code> is of length <code>numTaps+blockSize-1</code> words where <code>blockSize</code> is the number of input samples passed to <code>arm_fir_decimate_q31()</code>.
emilmont 1:fdd22bb7aa52 72 * <code>M</code> is the decimation factor.
emilmont 1:fdd22bb7aa52 73 */
emilmont 1:fdd22bb7aa52 74
emilmont 1:fdd22bb7aa52 75 arm_status arm_fir_decimate_init_q31(
emilmont 1:fdd22bb7aa52 76 arm_fir_decimate_instance_q31 * S,
emilmont 1:fdd22bb7aa52 77 uint16_t numTaps,
emilmont 1:fdd22bb7aa52 78 uint8_t M,
emilmont 1:fdd22bb7aa52 79 q31_t * pCoeffs,
emilmont 1:fdd22bb7aa52 80 q31_t * pState,
emilmont 1:fdd22bb7aa52 81 uint32_t blockSize)
emilmont 1:fdd22bb7aa52 82 {
emilmont 1:fdd22bb7aa52 83 arm_status status;
emilmont 1:fdd22bb7aa52 84
emilmont 1:fdd22bb7aa52 85 /* The size of the input block must be a multiple of the decimation factor */
emilmont 1:fdd22bb7aa52 86 if((blockSize % M) != 0u)
emilmont 1:fdd22bb7aa52 87 {
emilmont 1:fdd22bb7aa52 88 /* Set status as ARM_MATH_LENGTH_ERROR */
emilmont 1:fdd22bb7aa52 89 status = ARM_MATH_LENGTH_ERROR;
emilmont 1:fdd22bb7aa52 90 }
emilmont 1:fdd22bb7aa52 91 else
emilmont 1:fdd22bb7aa52 92 {
emilmont 1:fdd22bb7aa52 93 /* Assign filter taps */
emilmont 1:fdd22bb7aa52 94 S->numTaps = numTaps;
emilmont 1:fdd22bb7aa52 95
emilmont 1:fdd22bb7aa52 96 /* Assign coefficient pointer */
emilmont 1:fdd22bb7aa52 97 S->pCoeffs = pCoeffs;
emilmont 1:fdd22bb7aa52 98
emilmont 1:fdd22bb7aa52 99 /* Clear the state buffer. The size is always (blockSize + numTaps - 1) */
emilmont 1:fdd22bb7aa52 100 memset(pState, 0, (numTaps + (blockSize - 1)) * sizeof(q31_t));
emilmont 1:fdd22bb7aa52 101
emilmont 1:fdd22bb7aa52 102 /* Assign state pointer */
emilmont 1:fdd22bb7aa52 103 S->pState = pState;
emilmont 1:fdd22bb7aa52 104
emilmont 1:fdd22bb7aa52 105 /* Assign Decimation factor */
emilmont 1:fdd22bb7aa52 106 S->M = M;
emilmont 1:fdd22bb7aa52 107
emilmont 1:fdd22bb7aa52 108 status = ARM_MATH_SUCCESS;
emilmont 1:fdd22bb7aa52 109 }
emilmont 1:fdd22bb7aa52 110
emilmont 1:fdd22bb7aa52 111 return (status);
emilmont 1:fdd22bb7aa52 112
emilmont 1:fdd22bb7aa52 113 }
emilmont 1:fdd22bb7aa52 114
emilmont 1:fdd22bb7aa52 115 /**
emilmont 1:fdd22bb7aa52 116 * @} end of FIR_decimate group
emilmont 1:fdd22bb7aa52 117 */