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| 483170 | 1 | /* ---------------------------------------------------------------------- |
| Q | 2 | * Copyright (C) 2010-2014 ARM Limited. All rights reserved. |
| 3 | * | |
| 4 | * $Date: 19. March 2015 | |
| 5 | * $Revision: V.1.4.5 | |
| 6 | * | |
| 7 | * Project: CMSIS DSP Library | |
| 8 | * Title: arm_cfft_q31.c | |
| 9 | * | |
| 10 | * Description: Combined Radix Decimation in Frequency CFFT fixed point processing function | |
| 11 | * | |
| 12 | * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 | |
| 13 | * | |
| 14 | * Redistribution and use in source and binary forms, with or without | |
| 15 | * modification, are permitted provided that the following conditions | |
| 16 | * are met: | |
| 17 | * - Redistributions of source code must retain the above copyright | |
| 18 | * notice, this list of conditions and the following disclaimer. | |
| 19 | * - Redistributions in binary form must reproduce the above copyright | |
| 20 | * notice, this list of conditions and the following disclaimer in | |
| 21 | * the documentation and/or other materials provided with the | |
| 22 | * distribution. | |
| 23 | * - Neither the name of ARM LIMITED nor the names of its contributors | |
| 24 | * may be used to endorse or promote products derived from this | |
| 25 | * software without specific prior written permission. | |
| 26 | * | |
| 27 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
| 28 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
| 29 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS | |
| 30 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE | |
| 31 | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, | |
| 32 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, | |
| 33 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |
| 34 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER | |
| 35 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 36 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN | |
| 37 | * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
| 38 | * POSSIBILITY OF SUCH DAMAGE. | |
| 39 | * -------------------------------------------------------------------- */ | |
| 40 | ||
| 41 | #include "arm_math.h" | |
| 42 | ||
| 43 | extern void arm_radix4_butterfly_q31( | |
| 44 | q31_t * pSrc, | |
| 45 | uint32_t fftLen, | |
| 46 | q31_t * pCoef, | |
| 47 | uint32_t twidCoefModifier); | |
| 48 | ||
| 49 | extern void arm_radix4_butterfly_inverse_q31( | |
| 50 | q31_t * pSrc, | |
| 51 | uint32_t fftLen, | |
| 52 | q31_t * pCoef, | |
| 53 | uint32_t twidCoefModifier); | |
| 54 | ||
| 55 | extern void arm_bitreversal_32( | |
| 56 | uint32_t * pSrc, | |
| 57 | const uint16_t bitRevLen, | |
| 58 | const uint16_t * pBitRevTable); | |
| 59 | ||
| 60 | void arm_cfft_radix4by2_q31( | |
| 61 | q31_t * pSrc, | |
| 62 | uint32_t fftLen, | |
| 63 | const q31_t * pCoef); | |
| 64 | ||
| 65 | void arm_cfft_radix4by2_inverse_q31( | |
| 66 | q31_t * pSrc, | |
| 67 | uint32_t fftLen, | |
| 68 | const q31_t * pCoef); | |
| 69 | ||
| 70 | /** | |
| 71 | * @ingroup groupTransforms | |
| 72 | */ | |
| 73 | ||
| 74 | /** | |
| 75 | * @addtogroup ComplexFFT | |
| 76 | * @{ | |
| 77 | */ | |
| 78 | ||
| 79 | /** | |
| 80 | * @details | |
| 81 | * @brief Processing function for the fixed-point complex FFT in Q31 format. | |
| 82 | * @param[in] *S points to an instance of the fixed-point CFFT structure. | |
| 83 | * @param[in, out] *p1 points to the complex data buffer of size <code>2*fftLen</code>. Processing occurs in-place. | |
| 84 | * @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform. | |
| 85 | * @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output. | |
| 86 | * @return none. | |
| 87 | */ | |
| 88 | ||
| 89 | void arm_cfft_q31( | |
| 90 | const arm_cfft_instance_q31 * S, | |
| 91 | q31_t * p1, | |
| 92 | uint8_t ifftFlag, | |
| 93 | uint8_t bitReverseFlag) | |
| 94 | { | |
| 95 | uint32_t L = S->fftLen; | |
| 96 | ||
| 97 | if(ifftFlag == 1u) | |
| 98 | { | |
| 99 | switch (L) | |
| 100 | { | |
| 101 | case 16: | |
| 102 | case 64: | |
| 103 | case 256: | |
| 104 | case 1024: | |
| 105 | case 4096: | |
| 106 | arm_radix4_butterfly_inverse_q31 ( p1, L, (q31_t*)S->pTwiddle, 1 ); | |
| 107 | break; | |
| 108 | ||
| 109 | case 32: | |
| 110 | case 128: | |
| 111 | case 512: | |
| 112 | case 2048: | |
| 113 | arm_cfft_radix4by2_inverse_q31 ( p1, L, S->pTwiddle ); | |
| 114 | break; | |
| 115 | } | |
| 116 | } | |
| 117 | else | |
| 118 | { | |
| 119 | switch (L) | |
| 120 | { | |
| 121 | case 16: | |
| 122 | case 64: | |
| 123 | case 256: | |
| 124 | case 1024: | |
| 125 | case 4096: | |
| 126 | arm_radix4_butterfly_q31 ( p1, L, (q31_t*)S->pTwiddle, 1 ); | |
| 127 | break; | |
| 128 | ||
| 129 | case 32: | |
| 130 | case 128: | |
| 131 | case 512: | |
| 132 | case 2048: | |
| 133 | arm_cfft_radix4by2_q31 ( p1, L, S->pTwiddle ); | |
| 134 | break; | |
| 135 | } | |
| 136 | } | |
| 137 | ||
| 138 | if( bitReverseFlag ) | |
| 139 | arm_bitreversal_32((uint32_t*)p1,S->bitRevLength,S->pBitRevTable); | |
| 140 | } | |
| 141 | ||
| 142 | /** | |
| 143 | * @} end of ComplexFFT group | |
| 144 | */ | |
| 145 | ||
| 146 | void arm_cfft_radix4by2_q31( | |
| 147 | q31_t * pSrc, | |
| 148 | uint32_t fftLen, | |
| 149 | const q31_t * pCoef) | |
| 150 | { | |
| 151 | uint32_t i, l; | |
| 152 | uint32_t n2, ia; | |
| 153 | q31_t xt, yt, cosVal, sinVal; | |
| 154 | q31_t p0, p1; | |
| 155 | ||
| 156 | n2 = fftLen >> 1; | |
| 157 | ia = 0; | |
| 158 | for (i = 0; i < n2; i++) | |
| 159 | { | |
| 160 | cosVal = pCoef[2*ia]; | |
| 161 | sinVal = pCoef[2*ia + 1]; | |
| 162 | ia++; | |
| 163 | ||
| 164 | l = i + n2; | |
| 165 | xt = (pSrc[2 * i] >> 2) - (pSrc[2 * l] >> 2); | |
| 166 | pSrc[2 * i] = (pSrc[2 * i] >> 2) + (pSrc[2 * l] >> 2); | |
| 167 | ||
| 168 | yt = (pSrc[2 * i + 1] >> 2) - (pSrc[2 * l + 1] >> 2); | |
| 169 | pSrc[2 * i + 1] = (pSrc[2 * l + 1] >> 2) + (pSrc[2 * i + 1] >> 2); | |
| 170 | ||
| 171 | mult_32x32_keep32_R(p0, xt, cosVal); | |
| 172 | mult_32x32_keep32_R(p1, yt, cosVal); | |
| 173 | multAcc_32x32_keep32_R(p0, yt, sinVal); | |
| 174 | multSub_32x32_keep32_R(p1, xt, sinVal); | |
| 175 | ||
| 176 | pSrc[2u * l] = p0 << 1; | |
| 177 | pSrc[2u * l + 1u] = p1 << 1; | |
| 178 | ||
| 179 | } | |
| 180 | ||
| 181 | // first col | |
| 182 | arm_radix4_butterfly_q31( pSrc, n2, (q31_t*)pCoef, 2u); | |
| 183 | // second col | |
| 184 | arm_radix4_butterfly_q31( pSrc + fftLen, n2, (q31_t*)pCoef, 2u); | |
| 185 | ||
| 186 | for (i = 0; i < fftLen >> 1; i++) | |
| 187 | { | |
| 188 | p0 = pSrc[4*i+0]; | |
| 189 | p1 = pSrc[4*i+1]; | |
| 190 | xt = pSrc[4*i+2]; | |
| 191 | yt = pSrc[4*i+3]; | |
| 192 | ||
| 193 | p0 <<= 1; | |
| 194 | p1 <<= 1; | |
| 195 | xt <<= 1; | |
| 196 | yt <<= 1; | |
| 197 | ||
| 198 | pSrc[4*i+0] = p0; | |
| 199 | pSrc[4*i+1] = p1; | |
| 200 | pSrc[4*i+2] = xt; | |
| 201 | pSrc[4*i+3] = yt; | |
| 202 | } | |
| 203 | ||
| 204 | } | |
| 205 | ||
| 206 | void arm_cfft_radix4by2_inverse_q31( | |
| 207 | q31_t * pSrc, | |
| 208 | uint32_t fftLen, | |
| 209 | const q31_t * pCoef) | |
| 210 | { | |
| 211 | uint32_t i, l; | |
| 212 | uint32_t n2, ia; | |
| 213 | q31_t xt, yt, cosVal, sinVal; | |
| 214 | q31_t p0, p1; | |
| 215 | ||
| 216 | n2 = fftLen >> 1; | |
| 217 | ia = 0; | |
| 218 | for (i = 0; i < n2; i++) | |
| 219 | { | |
| 220 | cosVal = pCoef[2*ia]; | |
| 221 | sinVal = pCoef[2*ia + 1]; | |
| 222 | ia++; | |
| 223 | ||
| 224 | l = i + n2; | |
| 225 | xt = (pSrc[2 * i] >> 2) - (pSrc[2 * l] >> 2); | |
| 226 | pSrc[2 * i] = (pSrc[2 * i] >> 2) + (pSrc[2 * l] >> 2); | |
| 227 | ||
| 228 | yt = (pSrc[2 * i + 1] >> 2) - (pSrc[2 * l + 1] >> 2); | |
| 229 | pSrc[2 * i + 1] = (pSrc[2 * l + 1] >> 2) + (pSrc[2 * i + 1] >> 2); | |
| 230 | ||
| 231 | mult_32x32_keep32_R(p0, xt, cosVal); | |
| 232 | mult_32x32_keep32_R(p1, yt, cosVal); | |
| 233 | multSub_32x32_keep32_R(p0, yt, sinVal); | |
| 234 | multAcc_32x32_keep32_R(p1, xt, sinVal); | |
| 235 | ||
| 236 | pSrc[2u * l] = p0 << 1; | |
| 237 | pSrc[2u * l + 1u] = p1 << 1; | |
| 238 | ||
| 239 | } | |
| 240 | ||
| 241 | // first col | |
| 242 | arm_radix4_butterfly_inverse_q31( pSrc, n2, (q31_t*)pCoef, 2u); | |
| 243 | // second col | |
| 244 | arm_radix4_butterfly_inverse_q31( pSrc + fftLen, n2, (q31_t*)pCoef, 2u); | |
| 245 | ||
| 246 | for (i = 0; i < fftLen >> 1; i++) | |
| 247 | { | |
| 248 | p0 = pSrc[4*i+0]; | |
| 249 | p1 = pSrc[4*i+1]; | |
| 250 | xt = pSrc[4*i+2]; | |
| 251 | yt = pSrc[4*i+3]; | |
| 252 | ||
| 253 | p0 <<= 1; | |
| 254 | p1 <<= 1; | |
| 255 | xt <<= 1; | |
| 256 | yt <<= 1; | |
| 257 | ||
| 258 | pSrc[4*i+0] = p0; | |
| 259 | pSrc[4*i+1] = p1; | |
| 260 | pSrc[4*i+2] = xt; | |
| 261 | pSrc[4*i+3] = yt; | |
| 262 | } | |
| 263 | } | |
| 264 | ||
