arm_lms_norm_init_q31.c
103 lines
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CLexer
r71 | /*----------------------------------------------------------------------------- | |||
* Copyright (C) 2010 ARM Limited. All rights reserved. | ||||
* | ||||
* $Date: 15. July 2011 | ||||
* $Revision: V1.0.10 | ||||
* | ||||
* Project: CMSIS DSP Library | ||||
* Title: arm_lms_norm_init_q31.c | ||||
* | ||||
* Description: Q31 NLMS initialization function. | ||||
* | ||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 | ||||
* | ||||
* 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 Q31 normalized LMS filter. | ||||
* @param[in] *S points to an instance of the Q31 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 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_norm_q31()</code>. | ||||
*/ | ||||
void arm_lms_norm_init_q31( | ||||
arm_lms_norm_instance_q31 * S, | ||||
uint16_t numTaps, | ||||
q31_t * pCoeffs, | ||||
q31_t * pState, | ||||
q31_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(q31_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 = armRecipTableQ31; | ||||
/* Initialise Energy to zero */ | ||||
S->energy = 0; | ||||
/* Initialise x0 to zero */ | ||||
S->x0 = 0; | ||||
} | ||||
/** | ||||
* @} end of LMS_NORM group | ||||
*/ | ||||