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CMSIS DSP library

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cmsis_dsp/FilteringFunctions/arm_biquad_cascade_df2T_init_f64.c@5:3762170b6d4d, 2015-11-20 (annotated)

Committer:
mbed_official
Date:
Fri Nov 20 08:45:18 2015 +0000
Revision:
5:3762170b6d4d
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
mbed_official 5:3762170b6d4d 1 /*-----------------------------------------------------------------------------
mbed_official 5:3762170b6d4d 2 * Copyright (C) 2010-2014 ARM Limited. All rights reserved.
mbed_official 5:3762170b6d4d 3 *
mbed_official 5:3762170b6d4d 4 * $Date: 19. March 2015
mbed_official 5:3762170b6d4d 5 * $Revision: V.1.4.5
mbed_official 5:3762170b6d4d 6 *
mbed_official 5:3762170b6d4d 7 * Project: CMSIS DSP Library
mbed_official 5:3762170b6d4d 8 * Title: arm_biquad_cascade_df2T_init_f64.c
mbed_official 5:3762170b6d4d 9 *
mbed_official 5:3762170b6d4d 10 * Description: Initialization function for the floating-point transposed
mbed_official 5:3762170b6d4d 11 * direct form II Biquad cascade filter.
mbed_official 5:3762170b6d4d 12 *
mbed_official 5:3762170b6d4d 13 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
mbed_official 5:3762170b6d4d 14 *
mbed_official 5:3762170b6d4d 15 * Redistribution and use in source and binary forms, with or without
mbed_official 5:3762170b6d4d 16 * modification, are permitted provided that the following conditions
mbed_official 5:3762170b6d4d 17 * are met:
mbed_official 5:3762170b6d4d 18 * - Redistributions of source code must retain the above copyright
mbed_official 5:3762170b6d4d 19 * notice, this list of conditions and the following disclaimer.
mbed_official 5:3762170b6d4d 20 * - Redistributions in binary form must reproduce the above copyright
mbed_official 5:3762170b6d4d 21 * notice, this list of conditions and the following disclaimer in
mbed_official 5:3762170b6d4d 22 * the documentation and/or other materials provided with the
mbed_official 5:3762170b6d4d 23 * distribution.
mbed_official 5:3762170b6d4d 24 * - Neither the name of ARM LIMITED nor the names of its contributors
mbed_official 5:3762170b6d4d 25 * may be used to endorse or promote products derived from this
mbed_official 5:3762170b6d4d 26 * software without specific prior written permission.
mbed_official 5:3762170b6d4d 27 *
mbed_official 5:3762170b6d4d 28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
mbed_official 5:3762170b6d4d 29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
mbed_official 5:3762170b6d4d 30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
mbed_official 5:3762170b6d4d 31 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
mbed_official 5:3762170b6d4d 32 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
mbed_official 5:3762170b6d4d 33 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
mbed_official 5:3762170b6d4d 34 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
mbed_official 5:3762170b6d4d 35 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
mbed_official 5:3762170b6d4d 36 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
mbed_official 5:3762170b6d4d 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
mbed_official 5:3762170b6d4d 38 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
mbed_official 5:3762170b6d4d 39 * POSSIBILITY OF SUCH DAMAGE.
mbed_official 5:3762170b6d4d 40 * ---------------------------------------------------------------------------*/
mbed_official 5:3762170b6d4d 41
mbed_official 5:3762170b6d4d 42 #include "arm_math.h"
mbed_official 5:3762170b6d4d 43
mbed_official 5:3762170b6d4d 44 /**
mbed_official 5:3762170b6d4d 45 * @ingroup groupFilters
mbed_official 5:3762170b6d4d 46 */
mbed_official 5:3762170b6d4d 47
mbed_official 5:3762170b6d4d 48 /**
mbed_official 5:3762170b6d4d 49 * @addtogroup BiquadCascadeDF2T
mbed_official 5:3762170b6d4d 50 * @{
mbed_official 5:3762170b6d4d 51 */
mbed_official 5:3762170b6d4d 52
mbed_official 5:3762170b6d4d 53 /**
mbed_official 5:3762170b6d4d 54 * @brief Initialization function for the floating-point transposed direct form II Biquad cascade filter.
mbed_official 5:3762170b6d4d 55 * @param[in,out] *S points to an instance of the filter data structure.
mbed_official 5:3762170b6d4d 56 * @param[in] numStages number of 2nd order stages in the filter.
mbed_official 5:3762170b6d4d 57 * @param[in] *pCoeffs points to the filter coefficients.
mbed_official 5:3762170b6d4d 58 * @param[in] *pState points to the state buffer.
mbed_official 5:3762170b6d4d 59 * @return none
mbed_official 5:3762170b6d4d 60 *
mbed_official 5:3762170b6d4d 61 * <b>Coefficient and State Ordering:</b>
mbed_official 5:3762170b6d4d 62 * \par
mbed_official 5:3762170b6d4d 63 * The coefficients are stored in the array <code>pCoeffs</code> in the following order:
mbed_official 5:3762170b6d4d 64 * <pre>
mbed_official 5:3762170b6d4d 65 * {b10, b11, b12, a11, a12, b20, b21, b22, a21, a22, ...}
mbed_official 5:3762170b6d4d 66 * </pre>
mbed_official 5:3762170b6d4d 67 *
mbed_official 5:3762170b6d4d 68 * \par
mbed_official 5:3762170b6d4d 69 * where <code>b1x</code> and <code>a1x</code> are the coefficients for the first stage,
mbed_official 5:3762170b6d4d 70 * <code>b2x</code> and <code>a2x</code> are the coefficients for the second stage,
mbed_official 5:3762170b6d4d 71 * and so on. The <code>pCoeffs</code> array contains a total of <code>5*numStages</code> values.
mbed_official 5:3762170b6d4d 72 *
mbed_official 5:3762170b6d4d 73 * \par
mbed_official 5:3762170b6d4d 74 * The <code>pState</code> is a pointer to state array.
mbed_official 5:3762170b6d4d 75 * Each Biquad stage has 2 state variables <code>d1,</code> and <code>d2</code>.
mbed_official 5:3762170b6d4d 76 * The 2 state variables for stage 1 are first, then the 2 state variables for stage 2, and so on.
mbed_official 5:3762170b6d4d 77 * The state array has a total length of <code>2*numStages</code> values.
mbed_official 5:3762170b6d4d 78 * The state variables are updated after each block of data is processed; the coefficients are untouched.
mbed_official 5:3762170b6d4d 79 */
mbed_official 5:3762170b6d4d 80
mbed_official 5:3762170b6d4d 81 void arm_biquad_cascade_df2T_init_f64(
mbed_official 5:3762170b6d4d 82 arm_biquad_cascade_df2T_instance_f64 * S,
mbed_official 5:3762170b6d4d 83 uint8_t numStages,
mbed_official 5:3762170b6d4d 84 float64_t * pCoeffs,
mbed_official 5:3762170b6d4d 85 float64_t * pState)
mbed_official 5:3762170b6d4d 86 {
mbed_official 5:3762170b6d4d 87 /* Assign filter stages */
mbed_official 5:3762170b6d4d 88 S->numStages = numStages;
mbed_official 5:3762170b6d4d 89
mbed_official 5:3762170b6d4d 90 /* Assign coefficient pointer */
mbed_official 5:3762170b6d4d 91 S->pCoeffs = pCoeffs;
mbed_official 5:3762170b6d4d 92
mbed_official 5:3762170b6d4d 93 /* Clear state buffer and size is always 2 * numStages */
mbed_official 5:3762170b6d4d 94 memset(pState, 0, (2u * (uint32_t) numStages) * sizeof(float64_t));
mbed_official 5:3762170b6d4d 95
mbed_official 5:3762170b6d4d 96 /* Assign state pointer */
mbed_official 5:3762170b6d4d 97 S->pState = pState;
mbed_official 5:3762170b6d4d 98 }
mbed_official 5:3762170b6d4d 99
mbed_official 5:3762170b6d4d 100 /**
mbed_official 5:3762170b6d4d 101 * @} end of BiquadCascadeDF2T group
mbed_official 5:3762170b6d4d 102 */