| /*----------------------------------------------------------------------------- |
| * Copyright (C) 2010-2014 ARM Limited. All rights reserved. |
| * |
| * $Date: 19. March 2015 |
| * $Revision: V.1.4.5 |
| * |
| * 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 |
| * |
| * 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" |
| |
| /** |
| * @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 |
| */ |