Simon Ford
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
src/Cortex-M4-M3/FilteringFunctions/arm_fir_interpolate_init_q31.c@0:1014af42efd9, 2011-03-10 (annotated)
- Committer:
- simon
- Date:
- Thu Mar 10 15:07:50 2011 +0000
- Revision:
- 0:1014af42efd9
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| simon | 0:1014af42efd9 | 1 | /*----------------------------------------------------------------------------- |
| simon | 0:1014af42efd9 | 2 | * Copyright (C) 2010 ARM Limited. All rights reserved. |
| simon | 0:1014af42efd9 | 3 | * |
| simon | 0:1014af42efd9 | 4 | * $Date: 29. November 2010 |
| simon | 0:1014af42efd9 | 5 | * $Revision: V1.0.3 |
| simon | 0:1014af42efd9 | 6 | * |
| simon | 0:1014af42efd9 | 7 | * Project: CMSIS DSP Library |
| simon | 0:1014af42efd9 | 8 | * Title: arm_fir_interpolate_init_q31.c |
| simon | 0:1014af42efd9 | 9 | * |
| simon | 0:1014af42efd9 | 10 | * Description: Q31 FIR interpolator initialization function |
| simon | 0:1014af42efd9 | 11 | * |
| simon | 0:1014af42efd9 | 12 | * Target Processor: Cortex-M4/Cortex-M3 |
| simon | 0:1014af42efd9 | 13 | * |
| simon | 0:1014af42efd9 | 14 | * Version 1.0.3 2010/11/29 |
| simon | 0:1014af42efd9 | 15 | * Re-organized the CMSIS folders and updated documentation. |
| simon | 0:1014af42efd9 | 16 | * |
| simon | 0:1014af42efd9 | 17 | * Version 1.0.2 2010/11/11 |
| simon | 0:1014af42efd9 | 18 | * Documentation updated. |
| simon | 0:1014af42efd9 | 19 | * |
| simon | 0:1014af42efd9 | 20 | * Version 1.0.1 2010/10/05 |
| simon | 0:1014af42efd9 | 21 | * Production release and review comments incorporated. |
| simon | 0:1014af42efd9 | 22 | * |
| simon | 0:1014af42efd9 | 23 | * Version 1.0.0 2010/09/20 |
| simon | 0:1014af42efd9 | 24 | * Production release and review comments incorporated |
| simon | 0:1014af42efd9 | 25 | * |
| simon | 0:1014af42efd9 | 26 | * Version 0.0.7 2010/06/10 |
| simon | 0:1014af42efd9 | 27 | * Misra-C changes done |
| simon | 0:1014af42efd9 | 28 | * ---------------------------------------------------------------------------*/ |
| simon | 0:1014af42efd9 | 29 | |
| simon | 0:1014af42efd9 | 30 | #include "arm_math.h" |
| simon | 0:1014af42efd9 | 31 | |
| simon | 0:1014af42efd9 | 32 | /** |
| simon | 0:1014af42efd9 | 33 | * @ingroup groupFilters |
| simon | 0:1014af42efd9 | 34 | */ |
| simon | 0:1014af42efd9 | 35 | |
| simon | 0:1014af42efd9 | 36 | /** |
| simon | 0:1014af42efd9 | 37 | * @addtogroup FIR_Interpolate |
| simon | 0:1014af42efd9 | 38 | * @{ |
| simon | 0:1014af42efd9 | 39 | */ |
| simon | 0:1014af42efd9 | 40 | |
| simon | 0:1014af42efd9 | 41 | |
| simon | 0:1014af42efd9 | 42 | /** |
| simon | 0:1014af42efd9 | 43 | * @brief Initialization function for the Q31 FIR interpolator. |
| simon | 0:1014af42efd9 | 44 | * @param[in,out] *S points to an instance of the Q31 FIR interpolator structure. |
| simon | 0:1014af42efd9 | 45 | * @param[in] L upsample factor. |
| simon | 0:1014af42efd9 | 46 | * @param[in] numTaps number of filter coefficients in the filter. |
| simon | 0:1014af42efd9 | 47 | * @param[in] *pCoeffs points to the filter coefficient buffer. |
| simon | 0:1014af42efd9 | 48 | * @param[in] *pState points to the state buffer. |
| simon | 0:1014af42efd9 | 49 | * @param[in] blockSize number of input samples to process per call. |
| simon | 0:1014af42efd9 | 50 | * @return The function returns ARM_MATH_SUCCESS if initialization was successful or ARM_MATH_LENGTH_ERROR if |
| simon | 0:1014af42efd9 | 51 | * the filter length <code>numTaps</code> is not a multiple of the interpolation factor <code>L</code>. |
| simon | 0:1014af42efd9 | 52 | * |
| simon | 0:1014af42efd9 | 53 | * <b>Description:</b> |
| simon | 0:1014af42efd9 | 54 | * \par |
| simon | 0:1014af42efd9 | 55 | * <code>pCoeffs</code> points to the array of filter coefficients stored in time reversed order: |
| simon | 0:1014af42efd9 | 56 | * <pre> |
| simon | 0:1014af42efd9 | 57 | * {b[numTaps-1], b[numTaps-2], b[numTaps-2], ..., b[1], b[0]} |
| simon | 0:1014af42efd9 | 58 | * </pre> |
| simon | 0:1014af42efd9 | 59 | * The length of the filter <code>numTaps</code> must be a multiple of the interpolation factor <code>L</code>. |
| simon | 0:1014af42efd9 | 60 | * \par |
| simon | 0:1014af42efd9 | 61 | * <code>pState</code> points to the array of state variables. |
| simon | 0:1014af42efd9 | 62 | * <code>pState</code> is of length <code>(numTaps/L)+blockSize-1</code> words |
| simon | 0:1014af42efd9 | 63 | * where <code>blockSize</code> is the number of input samples processed by each call to <code>arm_fir_interpolate_q31()</code>. |
| simon | 0:1014af42efd9 | 64 | */ |
| simon | 0:1014af42efd9 | 65 | |
| simon | 0:1014af42efd9 | 66 | arm_status arm_fir_interpolate_init_q31( |
| simon | 0:1014af42efd9 | 67 | arm_fir_interpolate_instance_q31 * S, |
| simon | 0:1014af42efd9 | 68 | uint8_t L, |
| simon | 0:1014af42efd9 | 69 | uint16_t numTaps, |
| simon | 0:1014af42efd9 | 70 | q31_t * pCoeffs, |
| simon | 0:1014af42efd9 | 71 | q31_t * pState, |
| simon | 0:1014af42efd9 | 72 | uint32_t blockSize) |
| simon | 0:1014af42efd9 | 73 | { |
| simon | 0:1014af42efd9 | 74 | arm_status status; |
| simon | 0:1014af42efd9 | 75 | |
| simon | 0:1014af42efd9 | 76 | /* The filter length must be a multiple of the interpolation factor */ |
| simon | 0:1014af42efd9 | 77 | if((numTaps % L) != 0u) |
| simon | 0:1014af42efd9 | 78 | { |
| simon | 0:1014af42efd9 | 79 | /* Set status as ARM_MATH_LENGTH_ERROR */ |
| simon | 0:1014af42efd9 | 80 | status = ARM_MATH_LENGTH_ERROR; |
| simon | 0:1014af42efd9 | 81 | } |
| simon | 0:1014af42efd9 | 82 | else |
| simon | 0:1014af42efd9 | 83 | { |
| simon | 0:1014af42efd9 | 84 | |
| simon | 0:1014af42efd9 | 85 | /* Assign coefficient pointer */ |
| simon | 0:1014af42efd9 | 86 | S->pCoeffs = pCoeffs; |
| simon | 0:1014af42efd9 | 87 | |
| simon | 0:1014af42efd9 | 88 | /* Assign Interpolation factor */ |
| simon | 0:1014af42efd9 | 89 | S->L = L; |
| simon | 0:1014af42efd9 | 90 | |
| simon | 0:1014af42efd9 | 91 | /* Assign polyPhaseLength */ |
| simon | 0:1014af42efd9 | 92 | S->phaseLength = numTaps / L; |
| simon | 0:1014af42efd9 | 93 | |
| simon | 0:1014af42efd9 | 94 | /* Clear state buffer and size of buffer is always phaseLength + blockSize - 1 */ |
| simon | 0:1014af42efd9 | 95 | memset(pState, 0, |
| simon | 0:1014af42efd9 | 96 | (blockSize + ((uint32_t) S->phaseLength - 1u)) * sizeof(q31_t)); |
| simon | 0:1014af42efd9 | 97 | |
| simon | 0:1014af42efd9 | 98 | /* Assign state pointer */ |
| simon | 0:1014af42efd9 | 99 | S->pState = pState; |
| simon | 0:1014af42efd9 | 100 | |
| simon | 0:1014af42efd9 | 101 | status = ARM_MATH_SUCCESS; |
| simon | 0:1014af42efd9 | 102 | } |
| simon | 0:1014af42efd9 | 103 | |
| simon | 0:1014af42efd9 | 104 | return (status); |
| simon | 0:1014af42efd9 | 105 | |
| simon | 0:1014af42efd9 | 106 | } |
| simon | 0:1014af42efd9 | 107 | |
| simon | 0:1014af42efd9 | 108 | /** |
| simon | 0:1014af42efd9 | 109 | * @} end of FIR_Interpolate group |
| simon | 0:1014af42efd9 | 110 | */ |