arm_iir_lattice_init_q15.c

00001 /*-----------------------------------------------------------------------------  
00002 * Copyright (C) 2010 ARM Limited. All rights reserved.  
00003 *  
00004 * $Date:        29. November 2010  
00005 * $Revision:    V1.0.3  
00006 *  
00007 * Project:      CMSIS DSP Library  
00008 * Title:        arm_iir_lattice_init_q15.c  
00009 *  
00010 * Description:  Q15 IIR lattice filter initialization function.  
00011 *  
00012 * Target Processor: Cortex-M4/Cortex-M3
00013 *  
00014 * Version 1.0.3 2010/11/29 
00015 *    Re-organized the CMSIS folders and updated documentation.  
00016 *   
00017 * Version 1.0.2 2010/11/11  
00018 *    Documentation updated.   
00019 *  
00020 * Version 1.0.1 2010/10/05   
00021 *    Production release and review comments incorporated.  
00022 *  
00023 * Version 1.0.0 2010/09/20   
00024 *    Production release and review comments incorporated  
00025 *  
00026 * Version 0.0.7  2010/06/10   
00027 *    Misra-C changes done  
00028 * ---------------------------------------------------------------------------*/ 
00029  
00030 #include "arm_math.h" 
00031  
00032 /**  
00033  * @ingroup groupFilters  
00034  */ 
00035  
00036 /**  
00037  * @addtogroup IIR_Lattice  
00038  * @{  
00039  */ 
00040  
00041   /**  
00042    * @brief Initialization function for the Q15 IIR lattice filter.  
00043    * @param[in] *S points to an instance of the Q15 IIR lattice structure.  
00044    * @param[in] numStages  number of stages in the filter.  
00045    * @param[in] *pkCoeffs points to reflection coefficient buffer.  The array is of length numStages.  
00046    * @param[in] *pvCoeffs points to ladder coefficient buffer.  The array is of length numStages+1.  
00047    * @param[in] *pState points to state buffer.  The array is of length numStages+blockSize.  
00048    * @param[in] blockSize number of samples to process per call.  
00049    * @return none.  
00050    */ 
00051  
00052 void arm_iir_lattice_init_q15( 
00053   arm_iir_lattice_instance_q15 * S, 
00054   uint16_t numStages, 
00055   q15_t * pkCoeffs, 
00056   q15_t * pvCoeffs, 
00057   q15_t * pState, 
00058   uint32_t blockSize) 
00059 { 
00060   /* Assign filter taps */ 
00061   S->numStages = numStages; 
00062  
00063   /* Assign reflection coefficient pointer */ 
00064   S->pkCoeffs = pkCoeffs; 
00065  
00066   /* Assign ladder coefficient pointer */ 
00067   S->pvCoeffs = pvCoeffs; 
00068  
00069   /* Clear state buffer and size is always blockSize + numStages */ 
00070   memset(pState, 0, (numStages + blockSize) * sizeof(q15_t)); 
00071  
00072   /* Assign state pointer */ 
00073   S->pState = pState; 
00074  
00075  
00076 } 
00077  
00078 /**  
00079  * @} end of IIR_Lattice group  
00080  */