Diff: FilteringFunctions/arm_lms_norm_init_q15.c

Revision:

0:3d9c67d97d6f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/FilteringFunctions/arm_lms_norm_init_q15.c	Mon Jul 28 15:03:15 2014 +0000
@@ -0,0 +1,112 @@
+/*-----------------------------------------------------------------------------    
+* Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
+*    
+* $Date:        12. March 2014
+* $Revision: 	V1.4.3
+*    
+* Project: 	    CMSIS DSP Library    
+* Title:        arm_lms_norm_init_q15.c    
+*    
+* Description:  Q15 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 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    
+ */