CMSIS DSP Library from CMSIS 2.0. See http://www.onarm.com/cmsis/ for full details
Dependents: K22F_DSP_Matrix_least_square BNO055-ELEC3810 1BNO055 ECE4180Project--Slave2 ... more
Diff: src/Cortex-M4-M3/FilteringFunctions/arm_fir_interpolate_init_f32.c
- Revision:
- 0:1014af42efd9
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/Cortex-M4-M3/FilteringFunctions/arm_fir_interpolate_init_f32.c Thu Mar 10 15:07:50 2011 +0000 @@ -0,0 +1,110 @@ +/*----------------------------------------------------------------------------- +* Copyright (C) 2010 ARM Limited. All rights reserved. +* +* $Date: 29. November 2010 +* $Revision: V1.0.3 +* +* Project: CMSIS DSP Library +* Title: arm_fir_interpolate_init_f32.c +* +* Description: Floating-point FIR interpolator initialization function +* +* Target Processor: Cortex-M4/Cortex-M3 +* +* 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 + */