CMSIS DSP library
Dependents: performance_timer Surfboard_ gps2rtty Capstone ... more
Legacy Warning
This is an mbed 2 library. To learn more about mbed OS 5, visit the docs.
cmsis_dsp/FilteringFunctions/arm_fir_interpolate_init_f32.c
- Committer:
- emilmont
- Date:
- 2012-11-28
- Revision:
- 1:fdd22bb7aa52
- Child:
- 2:da51fb522205
File content as of revision 1:fdd22bb7aa52:
/*----------------------------------------------------------------------------- * Copyright (C) 2010 ARM Limited. All rights reserved. * * $Date: 15. February 2012 * $Revision: V1.1.0 * * Project: CMSIS DSP Library * Title: arm_fir_interpolate_init_f32.c * * Description: Floating-point FIR interpolator initialization function * * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 * * Version 1.1.0 2012/02/15 * Updated with more optimizations, bug fixes and minor API changes. * * 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 FIR_Interpolate * @{ */ /** * @brief Initialization function for the floating-point FIR interpolator. * @param[in,out] *S points to an instance of the floating-point FIR interpolator structure. * @param[in] L upsample factor. * @param[in] numTaps number of filter coefficients in the filter. * @param[in] *pCoeffs points to the filter coefficient buffer. * @param[in] *pState points to the state buffer. * @param[in] blockSize number of input samples to process per call. * @return The function returns ARM_MATH_SUCCESS if initialization was successful or ARM_MATH_LENGTH_ERROR if * the filter length <code>numTaps</code> is not a multiple of the interpolation factor <code>L</code>. * * <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[numTaps-2], ..., b[1], b[0]} * </pre> * The length of the filter <code>numTaps</code> must be a multiple of the interpolation factor <code>L</code>. * \par * <code>pState</code> points to the array of state variables. * <code>pState</code> is of length <code>(numTaps/L)+blockSize-1</code> words * where <code>blockSize</code> is the number of input samples processed by each call to <code>arm_fir_interpolate_f32()</code>. */ arm_status arm_fir_interpolate_init_f32( arm_fir_interpolate_instance_f32 * S, uint8_t L, uint16_t numTaps, float32_t * pCoeffs, float32_t * pState, uint32_t blockSize) { arm_status status; /* The filter length must be a multiple of the interpolation factor */ if((numTaps % L) != 0u) { /* Set status as ARM_MATH_LENGTH_ERROR */ status = ARM_MATH_LENGTH_ERROR; } else { /* Assign coefficient pointer */ S->pCoeffs = pCoeffs; /* Assign Interpolation factor */ S->L = L; /* Assign polyPhaseLength */ S->phaseLength = numTaps / L; /* Clear state buffer and size of state array is always phaseLength + blockSize - 1 */ memset(pState, 0, (blockSize + ((uint32_t) S->phaseLength - 1u)) * sizeof(float32_t)); /* Assign state pointer */ S->pState = pState; status = ARM_MATH_SUCCESS; } return (status); } /** * @} end of FIR_Interpolate group */