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CMSIS DSP library

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cmsis_dsp/FilteringFunctions/arm_iir_lattice_init_q15.c@1:fdd22bb7aa52, 2012-11-28 (annotated)

Committer:
emilmont
Date:
Wed Nov 28 12:30:09 2012 +0000
Revision:
1:fdd22bb7aa52
Child:
2:da51fb522205
DSP library code

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 1:fdd22bb7aa52 1 /*-----------------------------------------------------------------------------
emilmont 1:fdd22bb7aa52 2 * Copyright (C) 2010 ARM Limited. All rights reserved.
emilmont 1:fdd22bb7aa52 3 *
emilmont 1:fdd22bb7aa52 4 * $Date: 15. February 2012
emilmont 1:fdd22bb7aa52 5 * $Revision: V1.1.0
emilmont 1:fdd22bb7aa52 6 *
emilmont 1:fdd22bb7aa52 7 * Project: CMSIS DSP Library
emilmont 1:fdd22bb7aa52 8 * Title: arm_iir_lattice_init_q15.c
emilmont 1:fdd22bb7aa52 9 *
emilmont 1:fdd22bb7aa52 10 * Description: Q15 IIR lattice filter initialization function.
emilmont 1:fdd22bb7aa52 11 *
emilmont 1:fdd22bb7aa52 12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
emilmont 1:fdd22bb7aa52 13 *
emilmont 1:fdd22bb7aa52 14 * Version 1.1.0 2012/02/15
emilmont 1:fdd22bb7aa52 15 * Updated with more optimizations, bug fixes and minor API changes.
emilmont 1:fdd22bb7aa52 16 *
emilmont 1:fdd22bb7aa52 17 * Version 1.0.10 2011/7/15
emilmont 1:fdd22bb7aa52 18 * Big Endian support added and Merged M0 and M3/M4 Source code.
emilmont 1:fdd22bb7aa52 19 *
emilmont 1:fdd22bb7aa52 20 * Version 1.0.3 2010/11/29
emilmont 1:fdd22bb7aa52 21 * Re-organized the CMSIS folders and updated documentation.
emilmont 1:fdd22bb7aa52 22 *
emilmont 1:fdd22bb7aa52 23 * Version 1.0.2 2010/11/11
emilmont 1:fdd22bb7aa52 24 * Documentation updated.
emilmont 1:fdd22bb7aa52 25 *
emilmont 1:fdd22bb7aa52 26 * Version 1.0.1 2010/10/05
emilmont 1:fdd22bb7aa52 27 * Production release and review comments incorporated.
emilmont 1:fdd22bb7aa52 28 *
emilmont 1:fdd22bb7aa52 29 * Version 1.0.0 2010/09/20
emilmont 1:fdd22bb7aa52 30 * Production release and review comments incorporated
emilmont 1:fdd22bb7aa52 31 *
emilmont 1:fdd22bb7aa52 32 * Version 0.0.7 2010/06/10
emilmont 1:fdd22bb7aa52 33 * Misra-C changes done
emilmont 1:fdd22bb7aa52 34 * ---------------------------------------------------------------------------*/
emilmont 1:fdd22bb7aa52 35
emilmont 1:fdd22bb7aa52 36 #include "arm_math.h"
emilmont 1:fdd22bb7aa52 37
emilmont 1:fdd22bb7aa52 38 /**
emilmont 1:fdd22bb7aa52 39 * @ingroup groupFilters
emilmont 1:fdd22bb7aa52 40 */
emilmont 1:fdd22bb7aa52 41
emilmont 1:fdd22bb7aa52 42 /**
emilmont 1:fdd22bb7aa52 43 * @addtogroup IIR_Lattice
emilmont 1:fdd22bb7aa52 44 * @{
emilmont 1:fdd22bb7aa52 45 */
emilmont 1:fdd22bb7aa52 46
emilmont 1:fdd22bb7aa52 47 /**
emilmont 1:fdd22bb7aa52 48 * @brief Initialization function for the Q15 IIR lattice filter.
emilmont 1:fdd22bb7aa52 49 * @param[in] *S points to an instance of the Q15 IIR lattice structure.
emilmont 1:fdd22bb7aa52 50 * @param[in] numStages number of stages in the filter.
emilmont 1:fdd22bb7aa52 51 * @param[in] *pkCoeffs points to reflection coefficient buffer. The array is of length numStages.
emilmont 1:fdd22bb7aa52 52 * @param[in] *pvCoeffs points to ladder coefficient buffer. The array is of length numStages+1.
emilmont 1:fdd22bb7aa52 53 * @param[in] *pState points to state buffer. The array is of length numStages+blockSize.
emilmont 1:fdd22bb7aa52 54 * @param[in] blockSize number of samples to process per call.
emilmont 1:fdd22bb7aa52 55 * @return none.
emilmont 1:fdd22bb7aa52 56 */
emilmont 1:fdd22bb7aa52 57
emilmont 1:fdd22bb7aa52 58 void arm_iir_lattice_init_q15(
emilmont 1:fdd22bb7aa52 59 arm_iir_lattice_instance_q15 * S,
emilmont 1:fdd22bb7aa52 60 uint16_t numStages,
emilmont 1:fdd22bb7aa52 61 q15_t * pkCoeffs,
emilmont 1:fdd22bb7aa52 62 q15_t * pvCoeffs,
emilmont 1:fdd22bb7aa52 63 q15_t * pState,
emilmont 1:fdd22bb7aa52 64 uint32_t blockSize)
emilmont 1:fdd22bb7aa52 65 {
emilmont 1:fdd22bb7aa52 66 /* Assign filter taps */
emilmont 1:fdd22bb7aa52 67 S->numStages = numStages;
emilmont 1:fdd22bb7aa52 68
emilmont 1:fdd22bb7aa52 69 /* Assign reflection coefficient pointer */
emilmont 1:fdd22bb7aa52 70 S->pkCoeffs = pkCoeffs;
emilmont 1:fdd22bb7aa52 71
emilmont 1:fdd22bb7aa52 72 /* Assign ladder coefficient pointer */
emilmont 1:fdd22bb7aa52 73 S->pvCoeffs = pvCoeffs;
emilmont 1:fdd22bb7aa52 74
emilmont 1:fdd22bb7aa52 75 /* Clear state buffer and size is always blockSize + numStages */
emilmont 1:fdd22bb7aa52 76 memset(pState, 0, (numStages + blockSize) * sizeof(q15_t));
emilmont 1:fdd22bb7aa52 77
emilmont 1:fdd22bb7aa52 78 /* Assign state pointer */
emilmont 1:fdd22bb7aa52 79 S->pState = pState;
emilmont 1:fdd22bb7aa52 80
emilmont 1:fdd22bb7aa52 81
emilmont 1:fdd22bb7aa52 82 }
emilmont 1:fdd22bb7aa52 83
emilmont 1:fdd22bb7aa52 84 /**
emilmont 1:fdd22bb7aa52 85 * @} end of IIR_Lattice group
emilmont 1:fdd22bb7aa52 86 */