mbed-os 6.10 versione
cmsis_dsp/TransformFunctions/arm_cfft_radix4_init_q31.c@3:7a284390b0ce, 2013-11-08 (annotated)
- Committer:
- mbed_official
- Date:
- Fri Nov 08 13:45:10 2013 +0000
- Revision:
- 3:7a284390b0ce
- Parent:
- 2:da51fb522205
Synchronized with git revision e69956aba2f68a2a26ac26b051f8d349deaa1ce8
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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emilmont | 1:fdd22bb7aa52 | 1 | /* ---------------------------------------------------------------------- |
mbed_official | 3:7a284390b0ce | 2 | * Copyright (C) 2010-2013 ARM Limited. All rights reserved. |
emilmont | 1:fdd22bb7aa52 | 3 | * |
mbed_official | 3:7a284390b0ce | 4 | * $Date: 17. January 2013 |
mbed_official | 3:7a284390b0ce | 5 | * $Revision: V1.4.1 |
emilmont | 1:fdd22bb7aa52 | 6 | * |
emilmont | 2:da51fb522205 | 7 | * Project: CMSIS DSP Library |
emilmont | 2:da51fb522205 | 8 | * Title: arm_cfft_radix4_init_q31.c |
emilmont | 1:fdd22bb7aa52 | 9 | * |
emilmont | 2:da51fb522205 | 10 | * Description: Radix-4 Decimation in Frequency Q31 FFT & IFFT initialization function |
emilmont | 1:fdd22bb7aa52 | 11 | * |
emilmont | 1:fdd22bb7aa52 | 12 | * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 |
emilmont | 1:fdd22bb7aa52 | 13 | * |
mbed_official | 3:7a284390b0ce | 14 | * Redistribution and use in source and binary forms, with or without |
mbed_official | 3:7a284390b0ce | 15 | * modification, are permitted provided that the following conditions |
mbed_official | 3:7a284390b0ce | 16 | * are met: |
mbed_official | 3:7a284390b0ce | 17 | * - Redistributions of source code must retain the above copyright |
mbed_official | 3:7a284390b0ce | 18 | * notice, this list of conditions and the following disclaimer. |
mbed_official | 3:7a284390b0ce | 19 | * - Redistributions in binary form must reproduce the above copyright |
mbed_official | 3:7a284390b0ce | 20 | * notice, this list of conditions and the following disclaimer in |
mbed_official | 3:7a284390b0ce | 21 | * the documentation and/or other materials provided with the |
mbed_official | 3:7a284390b0ce | 22 | * distribution. |
mbed_official | 3:7a284390b0ce | 23 | * - Neither the name of ARM LIMITED nor the names of its contributors |
mbed_official | 3:7a284390b0ce | 24 | * may be used to endorse or promote products derived from this |
mbed_official | 3:7a284390b0ce | 25 | * software without specific prior written permission. |
mbed_official | 3:7a284390b0ce | 26 | * |
mbed_official | 3:7a284390b0ce | 27 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
mbed_official | 3:7a284390b0ce | 28 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
mbed_official | 3:7a284390b0ce | 29 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
mbed_official | 3:7a284390b0ce | 30 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
mbed_official | 3:7a284390b0ce | 31 | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
mbed_official | 3:7a284390b0ce | 32 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
mbed_official | 3:7a284390b0ce | 33 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
mbed_official | 3:7a284390b0ce | 34 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
mbed_official | 3:7a284390b0ce | 35 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
mbed_official | 3:7a284390b0ce | 36 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
mbed_official | 3:7a284390b0ce | 37 | * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
mbed_official | 3:7a284390b0ce | 38 | * POSSIBILITY OF SUCH DAMAGE. |
emilmont | 1:fdd22bb7aa52 | 39 | * -------------------------------------------------------------------- */ |
emilmont | 1:fdd22bb7aa52 | 40 | |
emilmont | 1:fdd22bb7aa52 | 41 | #include "arm_math.h" |
emilmont | 1:fdd22bb7aa52 | 42 | #include "arm_common_tables.h" |
emilmont | 1:fdd22bb7aa52 | 43 | |
emilmont | 1:fdd22bb7aa52 | 44 | /** |
emilmont | 1:fdd22bb7aa52 | 45 | * @ingroup groupTransforms |
emilmont | 1:fdd22bb7aa52 | 46 | */ |
emilmont | 1:fdd22bb7aa52 | 47 | |
emilmont | 1:fdd22bb7aa52 | 48 | /** |
mbed_official | 3:7a284390b0ce | 49 | * @addtogroup ComplexFFT |
emilmont | 1:fdd22bb7aa52 | 50 | * @{ |
emilmont | 1:fdd22bb7aa52 | 51 | */ |
emilmont | 1:fdd22bb7aa52 | 52 | |
emilmont | 1:fdd22bb7aa52 | 53 | /** |
emilmont | 1:fdd22bb7aa52 | 54 | * |
emilmont | 1:fdd22bb7aa52 | 55 | * @brief Initialization function for the Q31 CFFT/CIFFT. |
emilmont | 1:fdd22bb7aa52 | 56 | * @param[in,out] *S points to an instance of the Q31 CFFT/CIFFT structure. |
emilmont | 1:fdd22bb7aa52 | 57 | * @param[in] fftLen length of the FFT. |
emilmont | 1:fdd22bb7aa52 | 58 | * @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform. |
emilmont | 1:fdd22bb7aa52 | 59 | * @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output. |
emilmont | 1:fdd22bb7aa52 | 60 | * @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 | 61 | * |
emilmont | 1:fdd22bb7aa52 | 62 | * \par Description: |
emilmont | 1:fdd22bb7aa52 | 63 | * \par |
emilmont | 1:fdd22bb7aa52 | 64 | * The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed. |
emilmont | 1:fdd22bb7aa52 | 65 | * Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated |
emilmont | 1:fdd22bb7aa52 | 66 | * \par |
emilmont | 1:fdd22bb7aa52 | 67 | * The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order. |
emilmont | 1:fdd22bb7aa52 | 68 | * Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order. |
emilmont | 1:fdd22bb7aa52 | 69 | * \par |
emilmont | 2:da51fb522205 | 70 | * The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024. |
emilmont | 1:fdd22bb7aa52 | 71 | * \par |
emilmont | 1:fdd22bb7aa52 | 72 | * This Function also initializes Twiddle factor table pointer and Bit reversal table pointer. |
emilmont | 1:fdd22bb7aa52 | 73 | */ |
emilmont | 1:fdd22bb7aa52 | 74 | |
emilmont | 1:fdd22bb7aa52 | 75 | arm_status arm_cfft_radix4_init_q31( |
emilmont | 1:fdd22bb7aa52 | 76 | arm_cfft_radix4_instance_q31 * S, |
emilmont | 1:fdd22bb7aa52 | 77 | uint16_t fftLen, |
emilmont | 1:fdd22bb7aa52 | 78 | uint8_t ifftFlag, |
emilmont | 1:fdd22bb7aa52 | 79 | uint8_t bitReverseFlag) |
emilmont | 1:fdd22bb7aa52 | 80 | { |
emilmont | 1:fdd22bb7aa52 | 81 | /* Initialise the default arm status */ |
emilmont | 1:fdd22bb7aa52 | 82 | arm_status status = ARM_MATH_SUCCESS; |
emilmont | 1:fdd22bb7aa52 | 83 | /* Initialise the FFT length */ |
emilmont | 1:fdd22bb7aa52 | 84 | S->fftLen = fftLen; |
emilmont | 1:fdd22bb7aa52 | 85 | /* Initialise the Twiddle coefficient pointer */ |
emilmont | 1:fdd22bb7aa52 | 86 | S->pTwiddle = (q31_t *) twiddleCoefQ31; |
emilmont | 1:fdd22bb7aa52 | 87 | /* Initialise the Flag for selection of CFFT or CIFFT */ |
emilmont | 1:fdd22bb7aa52 | 88 | S->ifftFlag = ifftFlag; |
emilmont | 1:fdd22bb7aa52 | 89 | /* Initialise the Flag for calculation Bit reversal or not */ |
emilmont | 1:fdd22bb7aa52 | 90 | S->bitReverseFlag = bitReverseFlag; |
emilmont | 1:fdd22bb7aa52 | 91 | |
emilmont | 1:fdd22bb7aa52 | 92 | /* Initializations of Instance structure depending on the FFT length */ |
emilmont | 1:fdd22bb7aa52 | 93 | switch (S->fftLen) |
emilmont | 1:fdd22bb7aa52 | 94 | { |
emilmont | 1:fdd22bb7aa52 | 95 | /* Initializations of structure parameters for 4096 point FFT */ |
emilmont | 1:fdd22bb7aa52 | 96 | case 4096u: |
emilmont | 1:fdd22bb7aa52 | 97 | /* Initialise the twiddle coef modifier value */ |
emilmont | 1:fdd22bb7aa52 | 98 | S->twidCoefModifier = 1u; |
emilmont | 1:fdd22bb7aa52 | 99 | /* Initialise the bit reversal table modifier */ |
emilmont | 1:fdd22bb7aa52 | 100 | S->bitRevFactor = 1u; |
emilmont | 1:fdd22bb7aa52 | 101 | /* Initialise the bit reversal table pointer */ |
emilmont | 1:fdd22bb7aa52 | 102 | S->pBitRevTable = (uint16_t *) armBitRevTable; |
emilmont | 1:fdd22bb7aa52 | 103 | break; |
emilmont | 1:fdd22bb7aa52 | 104 | |
emilmont | 1:fdd22bb7aa52 | 105 | /* Initializations of structure parameters for 1024 point FFT */ |
emilmont | 1:fdd22bb7aa52 | 106 | case 1024u: |
emilmont | 1:fdd22bb7aa52 | 107 | /* Initialise the twiddle coef modifier value */ |
emilmont | 1:fdd22bb7aa52 | 108 | S->twidCoefModifier = 4u; |
emilmont | 1:fdd22bb7aa52 | 109 | /* Initialise the bit reversal table modifier */ |
emilmont | 1:fdd22bb7aa52 | 110 | S->bitRevFactor = 4u; |
emilmont | 1:fdd22bb7aa52 | 111 | /* Initialise the bit reversal table pointer */ |
emilmont | 1:fdd22bb7aa52 | 112 | S->pBitRevTable = (uint16_t *) & armBitRevTable[3]; |
emilmont | 1:fdd22bb7aa52 | 113 | break; |
emilmont | 1:fdd22bb7aa52 | 114 | |
emilmont | 1:fdd22bb7aa52 | 115 | case 256u: |
emilmont | 1:fdd22bb7aa52 | 116 | /* Initializations of structure parameters for 256 point FFT */ |
emilmont | 1:fdd22bb7aa52 | 117 | S->twidCoefModifier = 16u; |
emilmont | 1:fdd22bb7aa52 | 118 | S->bitRevFactor = 16u; |
emilmont | 1:fdd22bb7aa52 | 119 | S->pBitRevTable = (uint16_t *) & armBitRevTable[15]; |
emilmont | 1:fdd22bb7aa52 | 120 | break; |
emilmont | 1:fdd22bb7aa52 | 121 | |
emilmont | 1:fdd22bb7aa52 | 122 | case 64u: |
emilmont | 1:fdd22bb7aa52 | 123 | /* Initializations of structure parameters for 64 point FFT */ |
emilmont | 1:fdd22bb7aa52 | 124 | S->twidCoefModifier = 64u; |
emilmont | 1:fdd22bb7aa52 | 125 | S->bitRevFactor = 64u; |
emilmont | 1:fdd22bb7aa52 | 126 | S->pBitRevTable = (uint16_t *) & armBitRevTable[63]; |
emilmont | 1:fdd22bb7aa52 | 127 | break; |
emilmont | 1:fdd22bb7aa52 | 128 | |
emilmont | 1:fdd22bb7aa52 | 129 | case 16u: |
emilmont | 1:fdd22bb7aa52 | 130 | /* Initializations of structure parameters for 16 point FFT */ |
emilmont | 1:fdd22bb7aa52 | 131 | S->twidCoefModifier = 256u; |
emilmont | 1:fdd22bb7aa52 | 132 | S->bitRevFactor = 256u; |
emilmont | 1:fdd22bb7aa52 | 133 | S->pBitRevTable = (uint16_t *) & armBitRevTable[255]; |
emilmont | 1:fdd22bb7aa52 | 134 | break; |
emilmont | 1:fdd22bb7aa52 | 135 | |
emilmont | 1:fdd22bb7aa52 | 136 | default: |
emilmont | 1:fdd22bb7aa52 | 137 | /* Reporting argument error if fftSize is not valid value */ |
emilmont | 1:fdd22bb7aa52 | 138 | status = ARM_MATH_ARGUMENT_ERROR; |
emilmont | 1:fdd22bb7aa52 | 139 | break; |
emilmont | 1:fdd22bb7aa52 | 140 | } |
emilmont | 1:fdd22bb7aa52 | 141 | |
emilmont | 1:fdd22bb7aa52 | 142 | return (status); |
emilmont | 1:fdd22bb7aa52 | 143 | } |
emilmont | 1:fdd22bb7aa52 | 144 | |
emilmont | 1:fdd22bb7aa52 | 145 | /** |
mbed_official | 3:7a284390b0ce | 146 | * @} end of ComplexFFT group |
emilmont | 1:fdd22bb7aa52 | 147 | */ |