1 /*-----------------------------------------------------------------------------
2 * Copyright (C) 2010 ARM Limited. All rights reserved.
7 * Project: CMSIS DSP Library
8 * Title: arm_lms_norm_init_q31.c
10 * Description: Q31 NLMS initialization function.
12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
14 * Version 1.0.10 2011/7/15
15 * Big Endian support added and Merged M0 and M3/M4 Source code.
17 * Version 1.0.3 2010/11/29
18 * Re-organized the CMSIS folders and updated documentation.
20 * Version 1.0.2 2010/11/11
21 * Documentation updated.
23 * Version 1.0.1 2010/10/05
24 * Production release and review comments incorporated.
26 * Version 1.0.0 2010/09/20
27 * Production release and review comments incorporated
29 * Version 0.0.7 2010/06/10
30 * Misra-C changes done
31 * ---------------------------------------------------------------------------*/
34 #include "arm_common_tables.h"
37 * @addtogroup LMS_NORM
42 * @brief Initialization function for Q31 normalized LMS filter.
43 * @param[in] *S points to an instance of the Q31 normalized LMS filter structure.
44 * @param[in] numTaps number of filter coefficients.
45 * @param[in] *pCoeffs points to coefficient buffer.
46 * @param[in] *pState points to state buffer.
47 * @param[in] mu step size that controls filter coefficient updates.
48 * @param[in] blockSize number of samples to process.
49 * @param[in] postShift bit shift applied to coefficients.
54 * <code>pCoeffs</code> points to the array of filter coefficients stored in time reversed order:
56 * {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]}
58 * The initial filter coefficients serve as a starting point for the adaptive filter.
59 * <code>pState</code> points to an array of length <code>numTaps+blockSize-1</code> samples,
60 * where <code>blockSize</code> is the number of input samples processed by each call to <code>arm_lms_norm_q31()</code>.
63 void arm_lms_norm_init_q31(
64 arm_lms_norm_instance_q31 * S,
72 /* Assign filter taps */
75 /* Assign coefficient pointer */
78 /* Clear state buffer and size is always blockSize + numTaps - 1 */
79 memset(pState, 0, (numTaps + (blockSize - 1u)) * sizeof(q31_t));
81 /* Assign post Shift value applied to coefficients */
82 S->postShift = postShift;
84 /* Assign state pointer */
87 /* Assign Step size value */
90 /* Initialize reciprocal pointer table */
91 S->recipTable = armRecipTableQ31;
93 /* Initialise Energy to zero */
96 /* Initialise x0 to zero */
102 * @} end of LMS_NORM group