/*----------------------------------------------------------------------------- * Copyright (C) 2010 ARM Limited. All rights reserved. * * $Date: 15. July 2011 * $Revision: V1.0.10 * * Project: CMSIS DSP Library * Title: arm_iir_lattice_init_q15.c * * Description: Q15 IIR lattice filter 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" /** * @ingroup groupFilters */ /** * @addtogroup IIR_Lattice * @{ */ /** * @brief Initialization function for the Q15 IIR lattice filter. * @param[in] *S points to an instance of the Q15 IIR lattice structure. * @param[in] numStages number of stages in the filter. * @param[in] *pkCoeffs points to reflection coefficient buffer. The array is of length numStages. * @param[in] *pvCoeffs points to ladder coefficient buffer. The array is of length numStages+1. * @param[in] *pState points to state buffer. The array is of length numStages+blockSize. * @param[in] blockSize number of samples to process per call. * @return none. */ void arm_iir_lattice_init_q15( arm_iir_lattice_instance_q15 * S, uint16_t numStages, q15_t * pkCoeffs, q15_t * pvCoeffs, q15_t * pState, uint32_t blockSize) { /* Assign filter taps */ S->numStages = numStages; /* Assign reflection coefficient pointer */ S->pkCoeffs = pkCoeffs; /* Assign ladder coefficient pointer */ S->pvCoeffs = pvCoeffs; /* Clear state buffer and size is always blockSize + numStages */ memset(pState, 0, (numStages + blockSize) * sizeof(q15_t)); /* Assign state pointer */ S->pState = pState; } /** * @} end of IIR_Lattice group */