mbed official / mbed-dsp

CMSIS DSP library

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cmsis_dsp/FilteringFunctions/arm_fir_interpolate_init_f32.c@3:7a284390b0ce, 2013-11-08 (annotated)

Committer:
mbed_official
Date:
Fri Nov 08 13:45:10 2013 +0000
Revision:
3:7a284390b0ce
Parent:
2:da51fb522205 
Synchronized with git revision e69956aba2f68a2a26ac26b051f8d349deaa1ce8

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 1:fdd22bb7aa52 1 /*-----------------------------------------------------------------------------
mbed_official 3:7a284390b0ce 2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
emilmont 1:fdd22bb7aa52 3 *
mbed_official 3:7a284390b0ce 4 * $Date: 17. January 2013
mbed_official 3:7a284390b0ce 5 * $Revision: V1.4.1
emilmont 1:fdd22bb7aa52 6 *
emilmont 2:da51fb522205 7 * Project: CMSIS DSP Library
emilmont 1:fdd22bb7aa52 8 * Title: arm_fir_interpolate_init_f32.c
emilmont 1:fdd22bb7aa52 9 *
emilmont 1:fdd22bb7aa52 10 * Description: Floating-point FIR interpolator initialization function
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_Interpolate
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 floating-point FIR interpolator.
emilmont 1:fdd22bb7aa52 54 * @param[in,out] *S points to an instance of the floating-point FIR interpolator structure.
emilmont 1:fdd22bb7aa52 55 * @param[in] L upsample factor.
emilmont 1:fdd22bb7aa52 56 * @param[in] numTaps number of filter coefficients in the filter.
emilmont 1:fdd22bb7aa52 57 * @param[in] *pCoeffs points to the filter coefficient buffer.
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 * the filter length <code>numTaps</code> is not a multiple of the interpolation factor <code>L</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[numTaps-2], ..., b[1], b[0]}
emilmont 1:fdd22bb7aa52 68 * </pre>
emilmont 1:fdd22bb7aa52 69 * The length of the filter <code>numTaps</code> must be a multiple of the interpolation factor <code>L</code>.
emilmont 1:fdd22bb7aa52 70 * \par
emilmont 1:fdd22bb7aa52 71 * <code>pState</code> points to the array of state variables.
emilmont 1:fdd22bb7aa52 72 * <code>pState</code> is of length <code>(numTaps/L)+blockSize-1</code> words
emilmont 1:fdd22bb7aa52 73 * where <code>blockSize</code> is the number of input samples processed by each call to <code>arm_fir_interpolate_f32()</code>.
emilmont 1:fdd22bb7aa52 74 */
emilmont 1:fdd22bb7aa52 75
emilmont 1:fdd22bb7aa52 76 arm_status arm_fir_interpolate_init_f32(
emilmont 1:fdd22bb7aa52 77 arm_fir_interpolate_instance_f32 * S,
emilmont 1:fdd22bb7aa52 78 uint8_t L,
emilmont 1:fdd22bb7aa52 79 uint16_t numTaps,
emilmont 1:fdd22bb7aa52 80 float32_t * pCoeffs,
emilmont 1:fdd22bb7aa52 81 float32_t * pState,
emilmont 1:fdd22bb7aa52 82 uint32_t blockSize)
emilmont 1:fdd22bb7aa52 83 {
emilmont 1:fdd22bb7aa52 84 arm_status status;
emilmont 1:fdd22bb7aa52 85
emilmont 1:fdd22bb7aa52 86 /* The filter length must be a multiple of the interpolation factor */
emilmont 1:fdd22bb7aa52 87 if((numTaps % L) != 0u)
emilmont 1:fdd22bb7aa52 88 {
emilmont 1:fdd22bb7aa52 89 /* Set status as ARM_MATH_LENGTH_ERROR */
emilmont 1:fdd22bb7aa52 90 status = ARM_MATH_LENGTH_ERROR;
emilmont 1:fdd22bb7aa52 91 }
emilmont 1:fdd22bb7aa52 92 else
emilmont 1:fdd22bb7aa52 93 {
emilmont 1:fdd22bb7aa52 94
emilmont 1:fdd22bb7aa52 95 /* Assign coefficient pointer */
emilmont 1:fdd22bb7aa52 96 S->pCoeffs = pCoeffs;
emilmont 1:fdd22bb7aa52 97
emilmont 1:fdd22bb7aa52 98 /* Assign Interpolation factor */
emilmont 1:fdd22bb7aa52 99 S->L = L;
emilmont 1:fdd22bb7aa52 100
emilmont 1:fdd22bb7aa52 101 /* Assign polyPhaseLength */
emilmont 1:fdd22bb7aa52 102 S->phaseLength = numTaps / L;
emilmont 1:fdd22bb7aa52 103
emilmont 1:fdd22bb7aa52 104 /* Clear state buffer and size of state array is always phaseLength + blockSize - 1 */
emilmont 1:fdd22bb7aa52 105 memset(pState, 0,
emilmont 1:fdd22bb7aa52 106 (blockSize +
emilmont 1:fdd22bb7aa52 107 ((uint32_t) S->phaseLength - 1u)) * sizeof(float32_t));
emilmont 1:fdd22bb7aa52 108
emilmont 1:fdd22bb7aa52 109 /* Assign state pointer */
emilmont 1:fdd22bb7aa52 110 S->pState = pState;
emilmont 1:fdd22bb7aa52 111
emilmont 1:fdd22bb7aa52 112 status = ARM_MATH_SUCCESS;
emilmont 1:fdd22bb7aa52 113 }
emilmont 1:fdd22bb7aa52 114
emilmont 1:fdd22bb7aa52 115 return (status);
emilmont 1:fdd22bb7aa52 116
emilmont 1:fdd22bb7aa52 117 }
emilmont 1:fdd22bb7aa52 118
emilmont 1:fdd22bb7aa52 119 /**
emilmont 1:fdd22bb7aa52 120 * @} end of FIR_Interpolate group
emilmont 1:fdd22bb7aa52 121 */