Analog Devices / Mbed OS EVAL-CN0540-ARDZ

Dependencies:   platform_drivers LTC26X6 AD77681

CMSIS-DSP_Lib/Source/TransformFunctions/arm_bitreversal.c@1:9dd7c64b4a64, 2021-12-06 (annotated)

Committer:
jngarlitos
Date:
Mon Dec 06 05:22:28 2021 +0000
Revision:
1:9dd7c64b4a64
EVAL-CN0540-ARDZ mbed example program Initial Commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jngarlitos 1:9dd7c64b4a64 1 /* ----------------------------------------------------------------------
jngarlitos 1:9dd7c64b4a64 2 * Copyright (C) 2010-2014 ARM Limited. All rights reserved.
jngarlitos 1:9dd7c64b4a64 3 *
jngarlitos 1:9dd7c64b4a64 4 * $Date: 19. March 2015
jngarlitos 1:9dd7c64b4a64 5 * $Revision: V.1.4.5
jngarlitos 1:9dd7c64b4a64 6 *
jngarlitos 1:9dd7c64b4a64 7 * Project: CMSIS DSP Library
jngarlitos 1:9dd7c64b4a64 8 * Title: arm_bitreversal.c
jngarlitos 1:9dd7c64b4a64 9 *
jngarlitos 1:9dd7c64b4a64 10 * Description: This file has common tables like Bitreverse, reciprocal etc which are used across different functions
jngarlitos 1:9dd7c64b4a64 11 *
jngarlitos 1:9dd7c64b4a64 12 * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
jngarlitos 1:9dd7c64b4a64 13 *
jngarlitos 1:9dd7c64b4a64 14 * Redistribution and use in source and binary forms, with or without
jngarlitos 1:9dd7c64b4a64 15 * modification, are permitted provided that the following conditions
jngarlitos 1:9dd7c64b4a64 16 * are met:
jngarlitos 1:9dd7c64b4a64 17 * - Redistributions of source code must retain the above copyright
jngarlitos 1:9dd7c64b4a64 18 * notice, this list of conditions and the following disclaimer.
jngarlitos 1:9dd7c64b4a64 19 * - Redistributions in binary form must reproduce the above copyright
jngarlitos 1:9dd7c64b4a64 20 * notice, this list of conditions and the following disclaimer in
jngarlitos 1:9dd7c64b4a64 21 * the documentation and/or other materials provided with the
jngarlitos 1:9dd7c64b4a64 22 * distribution.
jngarlitos 1:9dd7c64b4a64 23 * - Neither the name of ARM LIMITED nor the names of its contributors
jngarlitos 1:9dd7c64b4a64 24 * may be used to endorse or promote products derived from this
jngarlitos 1:9dd7c64b4a64 25 * software without specific prior written permission.
jngarlitos 1:9dd7c64b4a64 26 *
jngarlitos 1:9dd7c64b4a64 27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
jngarlitos 1:9dd7c64b4a64 28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
jngarlitos 1:9dd7c64b4a64 29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
jngarlitos 1:9dd7c64b4a64 30 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
jngarlitos 1:9dd7c64b4a64 31 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
jngarlitos 1:9dd7c64b4a64 32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
jngarlitos 1:9dd7c64b4a64 33 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
jngarlitos 1:9dd7c64b4a64 34 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
jngarlitos 1:9dd7c64b4a64 35 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
jngarlitos 1:9dd7c64b4a64 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
jngarlitos 1:9dd7c64b4a64 37 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
jngarlitos 1:9dd7c64b4a64 38 * POSSIBILITY OF SUCH DAMAGE.
jngarlitos 1:9dd7c64b4a64 39 * -------------------------------------------------------------------- */
jngarlitos 1:9dd7c64b4a64 40
jngarlitos 1:9dd7c64b4a64 41 #include "arm_math.h"
jngarlitos 1:9dd7c64b4a64 42 #include "arm_common_tables.h"
jngarlitos 1:9dd7c64b4a64 43
jngarlitos 1:9dd7c64b4a64 44 /*
jngarlitos 1:9dd7c64b4a64 45 * @brief In-place bit reversal function.
jngarlitos 1:9dd7c64b4a64 46 * @param[in, out] *pSrc points to the in-place buffer of floating-point data type.
jngarlitos 1:9dd7c64b4a64 47 * @param[in] fftSize length of the FFT.
jngarlitos 1:9dd7c64b4a64 48 * @param[in] bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table.
jngarlitos 1:9dd7c64b4a64 49 * @param[in] *pBitRevTab points to the bit reversal table.
jngarlitos 1:9dd7c64b4a64 50 * @return none.
jngarlitos 1:9dd7c64b4a64 51 */
jngarlitos 1:9dd7c64b4a64 52
jngarlitos 1:9dd7c64b4a64 53 void arm_bitreversal_f32(
jngarlitos 1:9dd7c64b4a64 54 float32_t * pSrc,
jngarlitos 1:9dd7c64b4a64 55 uint16_t fftSize,
jngarlitos 1:9dd7c64b4a64 56 uint16_t bitRevFactor,
jngarlitos 1:9dd7c64b4a64 57 uint16_t * pBitRevTab)
jngarlitos 1:9dd7c64b4a64 58 {
jngarlitos 1:9dd7c64b4a64 59 uint16_t fftLenBy2, fftLenBy2p1;
jngarlitos 1:9dd7c64b4a64 60 uint16_t i, j;
jngarlitos 1:9dd7c64b4a64 61 float32_t in;
jngarlitos 1:9dd7c64b4a64 62
jngarlitos 1:9dd7c64b4a64 63 /* Initializations */
jngarlitos 1:9dd7c64b4a64 64 j = 0u;
jngarlitos 1:9dd7c64b4a64 65 fftLenBy2 = fftSize >> 1u;
jngarlitos 1:9dd7c64b4a64 66 fftLenBy2p1 = (fftSize >> 1u) + 1u;
jngarlitos 1:9dd7c64b4a64 67
jngarlitos 1:9dd7c64b4a64 68 /* Bit Reversal Implementation */
jngarlitos 1:9dd7c64b4a64 69 for (i = 0u; i <= (fftLenBy2 - 2u); i += 2u)
jngarlitos 1:9dd7c64b4a64 70 {
jngarlitos 1:9dd7c64b4a64 71 if(i < j)
jngarlitos 1:9dd7c64b4a64 72 {
jngarlitos 1:9dd7c64b4a64 73 /* pSrc[i] <-> pSrc[j]; */
jngarlitos 1:9dd7c64b4a64 74 in = pSrc[2u * i];
jngarlitos 1:9dd7c64b4a64 75 pSrc[2u * i] = pSrc[2u * j];
jngarlitos 1:9dd7c64b4a64 76 pSrc[2u * j] = in;
jngarlitos 1:9dd7c64b4a64 77
jngarlitos 1:9dd7c64b4a64 78 /* pSrc[i+1u] <-> pSrc[j+1u] */
jngarlitos 1:9dd7c64b4a64 79 in = pSrc[(2u * i) + 1u];
jngarlitos 1:9dd7c64b4a64 80 pSrc[(2u * i) + 1u] = pSrc[(2u * j) + 1u];
jngarlitos 1:9dd7c64b4a64 81 pSrc[(2u * j) + 1u] = in;
jngarlitos 1:9dd7c64b4a64 82
jngarlitos 1:9dd7c64b4a64 83 /* pSrc[i+fftLenBy2p1] <-> pSrc[j+fftLenBy2p1] */
jngarlitos 1:9dd7c64b4a64 84 in = pSrc[2u * (i + fftLenBy2p1)];
jngarlitos 1:9dd7c64b4a64 85 pSrc[2u * (i + fftLenBy2p1)] = pSrc[2u * (j + fftLenBy2p1)];
jngarlitos 1:9dd7c64b4a64 86 pSrc[2u * (j + fftLenBy2p1)] = in;
jngarlitos 1:9dd7c64b4a64 87
jngarlitos 1:9dd7c64b4a64 88 /* pSrc[i+fftLenBy2p1+1u] <-> pSrc[j+fftLenBy2p1+1u] */
jngarlitos 1:9dd7c64b4a64 89 in = pSrc[(2u * (i + fftLenBy2p1)) + 1u];
jngarlitos 1:9dd7c64b4a64 90 pSrc[(2u * (i + fftLenBy2p1)) + 1u] =
jngarlitos 1:9dd7c64b4a64 91 pSrc[(2u * (j + fftLenBy2p1)) + 1u];
jngarlitos 1:9dd7c64b4a64 92 pSrc[(2u * (j + fftLenBy2p1)) + 1u] = in;
jngarlitos 1:9dd7c64b4a64 93
jngarlitos 1:9dd7c64b4a64 94 }
jngarlitos 1:9dd7c64b4a64 95
jngarlitos 1:9dd7c64b4a64 96 /* pSrc[i+1u] <-> pSrc[j+1u] */
jngarlitos 1:9dd7c64b4a64 97 in = pSrc[2u * (i + 1u)];
jngarlitos 1:9dd7c64b4a64 98 pSrc[2u * (i + 1u)] = pSrc[2u * (j + fftLenBy2)];
jngarlitos 1:9dd7c64b4a64 99 pSrc[2u * (j + fftLenBy2)] = in;
jngarlitos 1:9dd7c64b4a64 100
jngarlitos 1:9dd7c64b4a64 101 /* pSrc[i+2u] <-> pSrc[j+2u] */
jngarlitos 1:9dd7c64b4a64 102 in = pSrc[(2u * (i + 1u)) + 1u];
jngarlitos 1:9dd7c64b4a64 103 pSrc[(2u * (i + 1u)) + 1u] = pSrc[(2u * (j + fftLenBy2)) + 1u];
jngarlitos 1:9dd7c64b4a64 104 pSrc[(2u * (j + fftLenBy2)) + 1u] = in;
jngarlitos 1:9dd7c64b4a64 105
jngarlitos 1:9dd7c64b4a64 106 /* Reading the index for the bit reversal */
jngarlitos 1:9dd7c64b4a64 107 j = *pBitRevTab;
jngarlitos 1:9dd7c64b4a64 108
jngarlitos 1:9dd7c64b4a64 109 /* Updating the bit reversal index depending on the fft length */
jngarlitos 1:9dd7c64b4a64 110 pBitRevTab += bitRevFactor;
jngarlitos 1:9dd7c64b4a64 111 }
jngarlitos 1:9dd7c64b4a64 112 }
jngarlitos 1:9dd7c64b4a64 113
jngarlitos 1:9dd7c64b4a64 114
jngarlitos 1:9dd7c64b4a64 115
jngarlitos 1:9dd7c64b4a64 116 /*
jngarlitos 1:9dd7c64b4a64 117 * @brief In-place bit reversal function.
jngarlitos 1:9dd7c64b4a64 118 * @param[in, out] *pSrc points to the in-place buffer of Q31 data type.
jngarlitos 1:9dd7c64b4a64 119 * @param[in] fftLen length of the FFT.
jngarlitos 1:9dd7c64b4a64 120 * @param[in] bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table
jngarlitos 1:9dd7c64b4a64 121 * @param[in] *pBitRevTab points to bit reversal table.
jngarlitos 1:9dd7c64b4a64 122 * @return none.
jngarlitos 1:9dd7c64b4a64 123 */
jngarlitos 1:9dd7c64b4a64 124
jngarlitos 1:9dd7c64b4a64 125 void arm_bitreversal_q31(
jngarlitos 1:9dd7c64b4a64 126 q31_t * pSrc,
jngarlitos 1:9dd7c64b4a64 127 uint32_t fftLen,
jngarlitos 1:9dd7c64b4a64 128 uint16_t bitRevFactor,
jngarlitos 1:9dd7c64b4a64 129 uint16_t * pBitRevTable)
jngarlitos 1:9dd7c64b4a64 130 {
jngarlitos 1:9dd7c64b4a64 131 uint32_t fftLenBy2, fftLenBy2p1, i, j;
jngarlitos 1:9dd7c64b4a64 132 q31_t in;
jngarlitos 1:9dd7c64b4a64 133
jngarlitos 1:9dd7c64b4a64 134 /* Initializations */
jngarlitos 1:9dd7c64b4a64 135 j = 0u;
jngarlitos 1:9dd7c64b4a64 136 fftLenBy2 = fftLen / 2u;
jngarlitos 1:9dd7c64b4a64 137 fftLenBy2p1 = (fftLen / 2u) + 1u;
jngarlitos 1:9dd7c64b4a64 138
jngarlitos 1:9dd7c64b4a64 139 /* Bit Reversal Implementation */
jngarlitos 1:9dd7c64b4a64 140 for (i = 0u; i <= (fftLenBy2 - 2u); i += 2u)
jngarlitos 1:9dd7c64b4a64 141 {
jngarlitos 1:9dd7c64b4a64 142 if(i < j)
jngarlitos 1:9dd7c64b4a64 143 {
jngarlitos 1:9dd7c64b4a64 144 /* pSrc[i] <-> pSrc[j]; */
jngarlitos 1:9dd7c64b4a64 145 in = pSrc[2u * i];
jngarlitos 1:9dd7c64b4a64 146 pSrc[2u * i] = pSrc[2u * j];
jngarlitos 1:9dd7c64b4a64 147 pSrc[2u * j] = in;
jngarlitos 1:9dd7c64b4a64 148
jngarlitos 1:9dd7c64b4a64 149 /* pSrc[i+1u] <-> pSrc[j+1u] */
jngarlitos 1:9dd7c64b4a64 150 in = pSrc[(2u * i) + 1u];
jngarlitos 1:9dd7c64b4a64 151 pSrc[(2u * i) + 1u] = pSrc[(2u * j) + 1u];
jngarlitos 1:9dd7c64b4a64 152 pSrc[(2u * j) + 1u] = in;
jngarlitos 1:9dd7c64b4a64 153
jngarlitos 1:9dd7c64b4a64 154 /* pSrc[i+fftLenBy2p1] <-> pSrc[j+fftLenBy2p1] */
jngarlitos 1:9dd7c64b4a64 155 in = pSrc[2u * (i + fftLenBy2p1)];
jngarlitos 1:9dd7c64b4a64 156 pSrc[2u * (i + fftLenBy2p1)] = pSrc[2u * (j + fftLenBy2p1)];
jngarlitos 1:9dd7c64b4a64 157 pSrc[2u * (j + fftLenBy2p1)] = in;
jngarlitos 1:9dd7c64b4a64 158
jngarlitos 1:9dd7c64b4a64 159 /* pSrc[i+fftLenBy2p1+1u] <-> pSrc[j+fftLenBy2p1+1u] */
jngarlitos 1:9dd7c64b4a64 160 in = pSrc[(2u * (i + fftLenBy2p1)) + 1u];
jngarlitos 1:9dd7c64b4a64 161 pSrc[(2u * (i + fftLenBy2p1)) + 1u] =
jngarlitos 1:9dd7c64b4a64 162 pSrc[(2u * (j + fftLenBy2p1)) + 1u];
jngarlitos 1:9dd7c64b4a64 163 pSrc[(2u * (j + fftLenBy2p1)) + 1u] = in;
jngarlitos 1:9dd7c64b4a64 164
jngarlitos 1:9dd7c64b4a64 165 }
jngarlitos 1:9dd7c64b4a64 166
jngarlitos 1:9dd7c64b4a64 167 /* pSrc[i+1u] <-> pSrc[j+1u] */
jngarlitos 1:9dd7c64b4a64 168 in = pSrc[2u * (i + 1u)];
jngarlitos 1:9dd7c64b4a64 169 pSrc[2u * (i + 1u)] = pSrc[2u * (j + fftLenBy2)];
jngarlitos 1:9dd7c64b4a64 170 pSrc[2u * (j + fftLenBy2)] = in;
jngarlitos 1:9dd7c64b4a64 171
jngarlitos 1:9dd7c64b4a64 172 /* pSrc[i+2u] <-> pSrc[j+2u] */
jngarlitos 1:9dd7c64b4a64 173 in = pSrc[(2u * (i + 1u)) + 1u];
jngarlitos 1:9dd7c64b4a64 174 pSrc[(2u * (i + 1u)) + 1u] = pSrc[(2u * (j + fftLenBy2)) + 1u];
jngarlitos 1:9dd7c64b4a64 175 pSrc[(2u * (j + fftLenBy2)) + 1u] = in;
jngarlitos 1:9dd7c64b4a64 176
jngarlitos 1:9dd7c64b4a64 177 /* Reading the index for the bit reversal */
jngarlitos 1:9dd7c64b4a64 178 j = *pBitRevTable;
jngarlitos 1:9dd7c64b4a64 179
jngarlitos 1:9dd7c64b4a64 180 /* Updating the bit reversal index depending on the fft length */
jngarlitos 1:9dd7c64b4a64 181 pBitRevTable += bitRevFactor;
jngarlitos 1:9dd7c64b4a64 182 }
jngarlitos 1:9dd7c64b4a64 183 }
jngarlitos 1:9dd7c64b4a64 184
jngarlitos 1:9dd7c64b4a64 185
jngarlitos 1:9dd7c64b4a64 186
jngarlitos 1:9dd7c64b4a64 187 /*
jngarlitos 1:9dd7c64b4a64 188 * @brief In-place bit reversal function.
jngarlitos 1:9dd7c64b4a64 189 * @param[in, out] *pSrc points to the in-place buffer of Q15 data type.
jngarlitos 1:9dd7c64b4a64 190 * @param[in] fftLen length of the FFT.
jngarlitos 1:9dd7c64b4a64 191 * @param[in] bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table
jngarlitos 1:9dd7c64b4a64 192 * @param[in] *pBitRevTab points to bit reversal table.
jngarlitos 1:9dd7c64b4a64 193 * @return none.
jngarlitos 1:9dd7c64b4a64 194 */
jngarlitos 1:9dd7c64b4a64 195
jngarlitos 1:9dd7c64b4a64 196 void arm_bitreversal_q15(
jngarlitos 1:9dd7c64b4a64 197 q15_t * pSrc16,
jngarlitos 1:9dd7c64b4a64 198 uint32_t fftLen,
jngarlitos 1:9dd7c64b4a64 199 uint16_t bitRevFactor,
jngarlitos 1:9dd7c64b4a64 200 uint16_t * pBitRevTab)
jngarlitos 1:9dd7c64b4a64 201 {
jngarlitos 1:9dd7c64b4a64 202 q31_t *pSrc = (q31_t *) pSrc16;
jngarlitos 1:9dd7c64b4a64 203 q31_t in;
jngarlitos 1:9dd7c64b4a64 204 uint32_t fftLenBy2, fftLenBy2p1;
jngarlitos 1:9dd7c64b4a64 205 uint32_t i, j;
jngarlitos 1:9dd7c64b4a64 206
jngarlitos 1:9dd7c64b4a64 207 /* Initializations */
jngarlitos 1:9dd7c64b4a64 208 j = 0u;
jngarlitos 1:9dd7c64b4a64 209 fftLenBy2 = fftLen / 2u;
jngarlitos 1:9dd7c64b4a64 210 fftLenBy2p1 = (fftLen / 2u) + 1u;
jngarlitos 1:9dd7c64b4a64 211
jngarlitos 1:9dd7c64b4a64 212 /* Bit Reversal Implementation */
jngarlitos 1:9dd7c64b4a64 213 for (i = 0u; i <= (fftLenBy2 - 2u); i += 2u)
jngarlitos 1:9dd7c64b4a64 214 {
jngarlitos 1:9dd7c64b4a64 215 if(i < j)
jngarlitos 1:9dd7c64b4a64 216 {
jngarlitos 1:9dd7c64b4a64 217 /* pSrc[i] <-> pSrc[j]; */
jngarlitos 1:9dd7c64b4a64 218 /* pSrc[i+1u] <-> pSrc[j+1u] */
jngarlitos 1:9dd7c64b4a64 219 in = pSrc[i];
jngarlitos 1:9dd7c64b4a64 220 pSrc[i] = pSrc[j];
jngarlitos 1:9dd7c64b4a64 221 pSrc[j] = in;
jngarlitos 1:9dd7c64b4a64 222
jngarlitos 1:9dd7c64b4a64 223 /* pSrc[i + fftLenBy2p1] <-> pSrc[j + fftLenBy2p1]; */
jngarlitos 1:9dd7c64b4a64 224 /* pSrc[i + fftLenBy2p1+1u] <-> pSrc[j + fftLenBy2p1+1u] */
jngarlitos 1:9dd7c64b4a64 225 in = pSrc[i + fftLenBy2p1];
jngarlitos 1:9dd7c64b4a64 226 pSrc[i + fftLenBy2p1] = pSrc[j + fftLenBy2p1];
jngarlitos 1:9dd7c64b4a64 227 pSrc[j + fftLenBy2p1] = in;
jngarlitos 1:9dd7c64b4a64 228 }
jngarlitos 1:9dd7c64b4a64 229
jngarlitos 1:9dd7c64b4a64 230 /* pSrc[i+1u] <-> pSrc[j+fftLenBy2]; */
jngarlitos 1:9dd7c64b4a64 231 /* pSrc[i+2] <-> pSrc[j+fftLenBy2+1u] */
jngarlitos 1:9dd7c64b4a64 232 in = pSrc[i + 1u];
jngarlitos 1:9dd7c64b4a64 233 pSrc[i + 1u] = pSrc[j + fftLenBy2];
jngarlitos 1:9dd7c64b4a64 234 pSrc[j + fftLenBy2] = in;
jngarlitos 1:9dd7c64b4a64 235
jngarlitos 1:9dd7c64b4a64 236 /* Reading the index for the bit reversal */
jngarlitos 1:9dd7c64b4a64 237 j = *pBitRevTab;
jngarlitos 1:9dd7c64b4a64 238
jngarlitos 1:9dd7c64b4a64 239 /* Updating the bit reversal index depending on the fft length */
jngarlitos 1:9dd7c64b4a64 240 pBitRevTab += bitRevFactor;
jngarlitos 1:9dd7c64b4a64 241 }
jngarlitos 1:9dd7c64b4a64 242 }