mbed-os 6.10 versione
cmsis_dsp/TransformFunctions/arm_cfft_radix4_init_f32.c@2:da51fb522205, 2013-05-30 (annotated)
- Committer:
- emilmont
- Date:
- Thu May 30 17:10:11 2013 +0100
- Revision:
- 2:da51fb522205
- Parent:
- 1:fdd22bb7aa52
- Child:
- 3:7a284390b0ce
Keep "cmsis-dsp" module in synch with its source
Who changed what in which revision?
User | Revision | Line number | New 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 | 2:da51fb522205 | 5 | * $Revision: V1.1.0 |
emilmont | 1:fdd22bb7aa52 | 6 | * |
emilmont | 2:da51fb522205 | 7 | * Project: CMSIS DSP Library |
emilmont | 2:da51fb522205 | 8 | * Title: arm_cfft_radix4_init_f32.c |
emilmont | 1:fdd22bb7aa52 | 9 | * |
emilmont | 2:da51fb522205 | 10 | * Description: Radix-4 Decimation in Frequency Floating-point CFFT & CIFFT 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 0.0.5 2010/04/26 |
emilmont | 2:da51fb522205 | 33 | * incorporated review comments and updated with latest CMSIS layer |
emilmont | 1:fdd22bb7aa52 | 34 | * |
emilmont | 1:fdd22bb7aa52 | 35 | * Version 0.0.3 2010/03/10 |
emilmont | 1:fdd22bb7aa52 | 36 | * Initial version |
emilmont | 1:fdd22bb7aa52 | 37 | * -------------------------------------------------------------------- */ |
emilmont | 1:fdd22bb7aa52 | 38 | |
emilmont | 1:fdd22bb7aa52 | 39 | |
emilmont | 1:fdd22bb7aa52 | 40 | #include "arm_math.h" |
emilmont | 1:fdd22bb7aa52 | 41 | #include "arm_common_tables.h" |
emilmont | 1:fdd22bb7aa52 | 42 | |
emilmont | 1:fdd22bb7aa52 | 43 | /** |
emilmont | 1:fdd22bb7aa52 | 44 | * @ingroup groupTransforms |
emilmont | 1:fdd22bb7aa52 | 45 | */ |
emilmont | 1:fdd22bb7aa52 | 46 | |
emilmont | 1:fdd22bb7aa52 | 47 | /** |
emilmont | 1:fdd22bb7aa52 | 48 | * @addtogroup Radix4_CFFT_CIFFT |
emilmont | 1:fdd22bb7aa52 | 49 | * @{ |
emilmont | 1:fdd22bb7aa52 | 50 | */ |
emilmont | 1:fdd22bb7aa52 | 51 | |
emilmont | 1:fdd22bb7aa52 | 52 | /** |
emilmont | 1:fdd22bb7aa52 | 53 | * @brief Initialization function for the floating-point CFFT/CIFFT. |
emilmont | 1:fdd22bb7aa52 | 54 | * @param[in,out] *S points to an instance of the floating-point CFFT/CIFFT structure. |
emilmont | 1:fdd22bb7aa52 | 55 | * @param[in] fftLen length of the FFT. |
emilmont | 1:fdd22bb7aa52 | 56 | * @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform. |
emilmont | 1:fdd22bb7aa52 | 57 | * @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output. |
emilmont | 1:fdd22bb7aa52 | 58 | * @return The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if <code>fftLen</code> is not a supported value. |
emilmont | 1:fdd22bb7aa52 | 59 | * |
emilmont | 1:fdd22bb7aa52 | 60 | * \par Description: |
emilmont | 1:fdd22bb7aa52 | 61 | * \par |
emilmont | 1:fdd22bb7aa52 | 62 | * The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed. |
emilmont | 1:fdd22bb7aa52 | 63 | * Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated |
emilmont | 1:fdd22bb7aa52 | 64 | * \par |
emilmont | 1:fdd22bb7aa52 | 65 | * The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order. |
emilmont | 1:fdd22bb7aa52 | 66 | * Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order. |
emilmont | 1:fdd22bb7aa52 | 67 | * \par |
emilmont | 2:da51fb522205 | 68 | * The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024. |
emilmont | 1:fdd22bb7aa52 | 69 | * \par |
emilmont | 1:fdd22bb7aa52 | 70 | * This Function also initializes Twiddle factor table pointer and Bit reversal table pointer. |
emilmont | 1:fdd22bb7aa52 | 71 | */ |
emilmont | 1:fdd22bb7aa52 | 72 | |
emilmont | 1:fdd22bb7aa52 | 73 | arm_status arm_cfft_radix4_init_f32( |
emilmont | 1:fdd22bb7aa52 | 74 | arm_cfft_radix4_instance_f32 * S, |
emilmont | 1:fdd22bb7aa52 | 75 | uint16_t fftLen, |
emilmont | 1:fdd22bb7aa52 | 76 | uint8_t ifftFlag, |
emilmont | 1:fdd22bb7aa52 | 77 | uint8_t bitReverseFlag) |
emilmont | 1:fdd22bb7aa52 | 78 | { |
emilmont | 1:fdd22bb7aa52 | 79 | /* Initialise the default arm status */ |
emilmont | 1:fdd22bb7aa52 | 80 | arm_status status = ARM_MATH_SUCCESS; |
emilmont | 1:fdd22bb7aa52 | 81 | |
emilmont | 1:fdd22bb7aa52 | 82 | /* Initialise the FFT length */ |
emilmont | 1:fdd22bb7aa52 | 83 | S->fftLen = fftLen; |
emilmont | 1:fdd22bb7aa52 | 84 | |
emilmont | 1:fdd22bb7aa52 | 85 | /* Initialise the Twiddle coefficient pointer */ |
emilmont | 1:fdd22bb7aa52 | 86 | S->pTwiddle = (float32_t *) twiddleCoef; |
emilmont | 1:fdd22bb7aa52 | 87 | |
emilmont | 1:fdd22bb7aa52 | 88 | /* Initialise the Flag for selection of CFFT or CIFFT */ |
emilmont | 1:fdd22bb7aa52 | 89 | S->ifftFlag = ifftFlag; |
emilmont | 1:fdd22bb7aa52 | 90 | |
emilmont | 1:fdd22bb7aa52 | 91 | /* Initialise the Flag for calculation Bit reversal or not */ |
emilmont | 1:fdd22bb7aa52 | 92 | S->bitReverseFlag = bitReverseFlag; |
emilmont | 1:fdd22bb7aa52 | 93 | |
emilmont | 1:fdd22bb7aa52 | 94 | /* Initializations of structure parameters depending on the FFT length */ |
emilmont | 1:fdd22bb7aa52 | 95 | switch (S->fftLen) |
emilmont | 1:fdd22bb7aa52 | 96 | { |
emilmont | 1:fdd22bb7aa52 | 97 | |
emilmont | 1:fdd22bb7aa52 | 98 | case 4096u: |
emilmont | 1:fdd22bb7aa52 | 99 | /* Initializations of structure parameters for 4096 point FFT */ |
emilmont | 1:fdd22bb7aa52 | 100 | |
emilmont | 1:fdd22bb7aa52 | 101 | /* Initialise the twiddle coef modifier value */ |
emilmont | 1:fdd22bb7aa52 | 102 | S->twidCoefModifier = 1u; |
emilmont | 1:fdd22bb7aa52 | 103 | /* Initialise the bit reversal table modifier */ |
emilmont | 1:fdd22bb7aa52 | 104 | S->bitRevFactor = 1u; |
emilmont | 1:fdd22bb7aa52 | 105 | /* Initialise the bit reversal table pointer */ |
emilmont | 1:fdd22bb7aa52 | 106 | S->pBitRevTable = (uint16_t *) armBitRevTable; |
emilmont | 1:fdd22bb7aa52 | 107 | /* Initialise the 1/fftLen Value */ |
emilmont | 1:fdd22bb7aa52 | 108 | S->onebyfftLen = 0.000244140625; |
emilmont | 1:fdd22bb7aa52 | 109 | break; |
emilmont | 1:fdd22bb7aa52 | 110 | |
emilmont | 1:fdd22bb7aa52 | 111 | case 1024u: |
emilmont | 1:fdd22bb7aa52 | 112 | /* Initializations of structure parameters for 1024 point FFT */ |
emilmont | 1:fdd22bb7aa52 | 113 | |
emilmont | 1:fdd22bb7aa52 | 114 | /* Initialise the twiddle coef modifier value */ |
emilmont | 1:fdd22bb7aa52 | 115 | S->twidCoefModifier = 4u; |
emilmont | 1:fdd22bb7aa52 | 116 | /* Initialise the bit reversal table modifier */ |
emilmont | 1:fdd22bb7aa52 | 117 | S->bitRevFactor = 4u; |
emilmont | 1:fdd22bb7aa52 | 118 | /* Initialise the bit reversal table pointer */ |
emilmont | 1:fdd22bb7aa52 | 119 | S->pBitRevTable = (uint16_t *) & armBitRevTable[3]; |
emilmont | 1:fdd22bb7aa52 | 120 | /* Initialise the 1/fftLen Value */ |
emilmont | 1:fdd22bb7aa52 | 121 | S->onebyfftLen = 0.0009765625f; |
emilmont | 1:fdd22bb7aa52 | 122 | break; |
emilmont | 1:fdd22bb7aa52 | 123 | |
emilmont | 1:fdd22bb7aa52 | 124 | |
emilmont | 1:fdd22bb7aa52 | 125 | case 256u: |
emilmont | 1:fdd22bb7aa52 | 126 | /* Initializations of structure parameters for 256 point FFT */ |
emilmont | 1:fdd22bb7aa52 | 127 | S->twidCoefModifier = 16u; |
emilmont | 1:fdd22bb7aa52 | 128 | S->bitRevFactor = 16u; |
emilmont | 1:fdd22bb7aa52 | 129 | S->pBitRevTable = (uint16_t *) & armBitRevTable[15]; |
emilmont | 1:fdd22bb7aa52 | 130 | S->onebyfftLen = 0.00390625f; |
emilmont | 1:fdd22bb7aa52 | 131 | break; |
emilmont | 1:fdd22bb7aa52 | 132 | |
emilmont | 1:fdd22bb7aa52 | 133 | case 64u: |
emilmont | 1:fdd22bb7aa52 | 134 | /* Initializations of structure parameters for 64 point FFT */ |
emilmont | 1:fdd22bb7aa52 | 135 | S->twidCoefModifier = 64u; |
emilmont | 1:fdd22bb7aa52 | 136 | S->bitRevFactor = 64u; |
emilmont | 1:fdd22bb7aa52 | 137 | S->pBitRevTable = (uint16_t *) & armBitRevTable[63]; |
emilmont | 1:fdd22bb7aa52 | 138 | S->onebyfftLen = 0.015625f; |
emilmont | 1:fdd22bb7aa52 | 139 | break; |
emilmont | 1:fdd22bb7aa52 | 140 | |
emilmont | 1:fdd22bb7aa52 | 141 | case 16u: |
emilmont | 1:fdd22bb7aa52 | 142 | /* Initializations of structure parameters for 16 point FFT */ |
emilmont | 1:fdd22bb7aa52 | 143 | S->twidCoefModifier = 256u; |
emilmont | 1:fdd22bb7aa52 | 144 | S->bitRevFactor = 256u; |
emilmont | 1:fdd22bb7aa52 | 145 | S->pBitRevTable = (uint16_t *) & armBitRevTable[255]; |
emilmont | 1:fdd22bb7aa52 | 146 | S->onebyfftLen = 0.0625f; |
emilmont | 1:fdd22bb7aa52 | 147 | break; |
emilmont | 1:fdd22bb7aa52 | 148 | |
emilmont | 1:fdd22bb7aa52 | 149 | |
emilmont | 1:fdd22bb7aa52 | 150 | default: |
emilmont | 1:fdd22bb7aa52 | 151 | /* Reporting argument error if fftSize is not valid value */ |
emilmont | 1:fdd22bb7aa52 | 152 | status = ARM_MATH_ARGUMENT_ERROR; |
emilmont | 1:fdd22bb7aa52 | 153 | break; |
emilmont | 1:fdd22bb7aa52 | 154 | } |
emilmont | 1:fdd22bb7aa52 | 155 | |
emilmont | 1:fdd22bb7aa52 | 156 | return (status); |
emilmont | 1:fdd22bb7aa52 | 157 | } |
emilmont | 1:fdd22bb7aa52 | 158 | |
emilmont | 1:fdd22bb7aa52 | 159 | /** |
emilmont | 1:fdd22bb7aa52 | 160 | * @} end of Radix4_CFFT_CIFFT group |
emilmont | 1:fdd22bb7aa52 | 161 | */ |