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Diffstat (limited to 'DSP_Lib/Source/FilteringFunctions/arm_lms_norm_init_q31.c')
-rw-r--r-- | DSP_Lib/Source/FilteringFunctions/arm_lms_norm_init_q31.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/DSP_Lib/Source/FilteringFunctions/arm_lms_norm_init_q31.c b/DSP_Lib/Source/FilteringFunctions/arm_lms_norm_init_q31.c new file mode 100644 index 0000000..9ada3a0 --- /dev/null +++ b/DSP_Lib/Source/FilteringFunctions/arm_lms_norm_init_q31.c @@ -0,0 +1,111 @@ +/*----------------------------------------------------------------------------- +* Copyright (C) 2010-2014 ARM Limited. All rights reserved. +* +* $Date: 19. March 2015 +* $Revision: V.1.4.5 +* +* Project: CMSIS DSP Library +* Title: arm_lms_norm_init_q31.c +* +* Description: Q31 NLMS initialization function. +* +* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 +* +* Redistribution and use in source and binary forms, with or without +* modification, are permitted provided that the following conditions +* are met: +* - Redistributions of source code must retain the above copyright +* notice, this list of conditions and the following disclaimer. +* - Redistributions in binary form must reproduce the above copyright +* notice, this list of conditions and the following disclaimer in +* the documentation and/or other materials provided with the +* distribution. +* - Neither the name of ARM LIMITED nor the names of its contributors +* may be used to endorse or promote products derived from this +* software without specific prior written permission. +* +* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS +* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE +* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, +* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +* POSSIBILITY OF SUCH DAMAGE. +* ---------------------------------------------------------------------------*/ + +#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 = (q31_t *) armRecipTableQ31; + + /* Initialise Energy to zero */ + S->energy = 0; + + /* Initialise x0 to zero */ + S->x0 = 0; + +} + +/** + * @} end of LMS_NORM group + */ |