CMSIS DSP library
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cmsis_dsp/FilteringFunctions/arm_lms_norm_init_q15.c
- Committer:
- emilmont
- Date:
- 2012-11-28
- Revision:
- 1:fdd22bb7aa52
- Child:
- 2:da51fb522205
File content as of revision 1:fdd22bb7aa52:
/*----------------------------------------------------------------------------- * Copyright (C) 2010 ARM Limited. All rights reserved. * * $Date: 15. February 2012 * $Revision: V1.1.0 * * Project: CMSIS DSP Library * Title: arm_lms_norm_init_q15.c * * Description: Q15 NLMS 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" #include "arm_common_tables.h" /** * @addtogroup LMS_NORM * @{ */ /** * @brief Initialization function for Q15 normalized LMS filter. * @param[in] *S points to an instance of the Q15 normalized 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. * * <b>Description:</b> * \par * <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 the array of state variables and size of array is * <code>numTaps+blockSize-1</code> samples, where <code>blockSize</code> is the number of input samples processed * by each call to <code>arm_lms_norm_q15()</code>. */ void arm_lms_norm_init_q15( arm_lms_norm_instance_q15 * S, uint16_t numTaps, q15_t * pCoeffs, q15_t * pState, q15_t mu, uint32_t blockSize, uint8_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, (numTaps + (blockSize - 1u)) * sizeof(q15_t)); /* Assign post Shift value applied to coefficients */ S->postShift = postShift; /* Assign state pointer */ S->pState = pState; /* Assign Step size value */ S->mu = mu; /* Initialize reciprocal pointer table */ S->recipTable = (q15_t *) armRecipTableQ15; /* Initialise Energy to zero */ S->energy = 0; /* Initialise x0 to zero */ S->x0 = 0; } /** * @} end of LMS_NORM group */