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/*-----------------------------------------------------------------------------
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* Copyright (C) 2010 ARM Limited. All rights reserved.
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*
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* $Date: 15. July 2011
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* $Revision: V1.0.10
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*
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* Project: CMSIS DSP Library
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* Title: arm_lms_init_q31.c
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*
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* Description: Q31 LMS filter initialization function.
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*
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* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
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*
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* Version 1.0.10 2011/7/15
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* Big Endian support added and Merged M0 and M3/M4 Source code.
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*
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* Version 1.0.3 2010/11/29
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* Re-organized the CMSIS folders and updated documentation.
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*
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* Version 1.0.2 2010/11/11
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* Documentation updated.
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*
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* Version 1.0.1 2010/10/05
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* Production release and review comments incorporated.
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*
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* Version 1.0.0 2010/09/20
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* Production release and review comments incorporated
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*
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* Version 0.0.7 2010/06/10
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* Misra-C changes done
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* ---------------------------------------------------------------------------*/
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#include "arm_math.h"
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/**
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* @ingroup groupFilters
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*/
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/**
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* @addtogroup LMS
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* @{
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*/
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/**
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* @brief Initialization function for Q31 LMS filter.
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* @param[in] *S points to an instance of the Q31 LMS filter structure.
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* @param[in] numTaps number of filter coefficients.
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* @param[in] *pCoeffs points to coefficient buffer.
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* @param[in] *pState points to state buffer.
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* @param[in] mu step size that controls filter coefficient updates.
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* @param[in] blockSize number of samples to process.
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* @param[in] postShift bit shift applied to coefficients.
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* @return none.
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*
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* \par Description:
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* <code>pCoeffs</code> points to the array of filter coefficients stored in time reversed order:
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* <pre>
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* {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]}
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* </pre>
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* The initial filter coefficients serve as a starting point for the adaptive filter.
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* <code>pState</code> points to an array of length <code>numTaps+blockSize-1</code> samples,
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* where <code>blockSize</code> is the number of input samples processed by each call to
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* <code>arm_lms_q31()</code>.
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*/
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void arm_lms_init_q31(
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arm_lms_instance_q31 * S,
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uint16_t numTaps,
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q31_t * pCoeffs,
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q31_t * pState,
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q31_t mu,
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uint32_t blockSize,
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uint32_t postShift)
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{
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/* Assign filter taps */
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S->numTaps = numTaps;
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/* Assign coefficient pointer */
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S->pCoeffs = pCoeffs;
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/* Clear state buffer and size is always blockSize + numTaps - 1 */
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memset(pState, 0, ((uint32_t) numTaps + (blockSize - 1u)) * sizeof(q31_t));
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/* Assign state pointer */
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S->pState = pState;
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/* Assign Step size value */
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S->mu = mu;
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/* Assign postShift value to be applied */
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S->postShift = postShift;
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}
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/**
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* @} end of LMS group
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*/
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