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/*-----------------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date: 15. February 2012
* $Revision: V1.1.0
*
* Project: CMSIS DSP Library
* Title: arm_lms_init_q31.c
*
* Description: Q31 LMS filter initialization function.
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Version 1.1.0 2012/02/15
* Updated with more optimizations, bug fixes and minor API changes.
*
* Version 1.0.10 2011/7/15
* Big Endian support added and Merged M0 and M3/M4 Source code.
*
* Version 1.0.3 2010/11/29
* Re-organized the CMSIS folders and updated documentation.
*
* Version 1.0.2 2010/11/11
* Documentation updated.
*
* Version 1.0.1 2010/10/05
* Production release and review comments incorporated.
*
* Version 1.0.0 2010/09/20
* Production release and review comments incorporated
*
* Version 0.0.7 2010/06/10
* Misra-C changes done
* ---------------------------------------------------------------------------*/
#include "arm_math.h"
/**
* @ingroup groupFilters
*/
/**
* @addtogroup LMS
* @{
*/
/**
* @brief Initialization function for Q31 LMS filter.
* @param[in] *S points to an instance of the Q31 LMS filter structure.
* @param[in] numTaps number of filter coefficients.
* @param[in] *pCoeffs points to coefficient buffer.
* @param[in] *pState points to state buffer.
* @param[in] mu step size that controls filter coefficient updates.
* @param[in] blockSize number of samples to process.
* @param[in] postShift bit shift applied to coefficients.
* @return none.
*
* \par Description:
* <code>pCoeffs</code> points to the array of filter coefficients stored in time reversed order:
* <pre>
* {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]}
* </pre>
* The initial filter coefficients serve as a starting point for the adaptive filter.
* <code>pState</code> points to an array 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_lms_q31()</code>.
*/
void arm_lms_init_q31(
arm_lms_instance_q31 * S,
uint16_t numTaps,
q31_t * pCoeffs,
q31_t * pState,
q31_t mu,
uint32_t blockSize,
uint32_t postShift)
{
/* Assign filter taps */
S->numTaps = numTaps;
/* Assign coefficient pointer */
S->pCoeffs = pCoeffs;
/* Clear state buffer and size is always blockSize + numTaps - 1 */
memset(pState, 0, ((uint32_t) numTaps + (blockSize - 1u)) * sizeof(q31_t));
/* Assign state pointer */
S->pState = pState;
/* Assign Step size value */
S->mu = mu;
/* Assign postShift value to be applied */
S->postShift = postShift;
}
/**
* @} end of LMS group
*/
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