CMSIS DSP Software Library: arm_sin_q15.c Source File Main Page Modules Data Structures Files Examples File List Globals arm_sin_q15.c Go to the documentation of this file.00001 /* ---------------------------------------------------------------------- 00002 * Copyright (C) 2010 ARM Limited. All rights reserved. 00003 * 00004 * $Date: 29. November 2010 00005 * $Revision: V1.0.3 00006 * 00007 * Project: CMSIS DSP Library 00008 * Title: arm_sin_q15.c 00009 * 00010 * Description: Fast sine calculation for Q15 values. 00011 * 00012 * Target Processor: Cortex-M4/Cortex-M3 00013 * 00014 * Version 1.0.3 2010/11/29 00015 * Re-organized the CMSIS folders and updated documentation. 00016 * 00017 * Version 1.0.2 2010/11/11 00018 * Documentation updated. 00019 * 00020 * Version 1.0.1 2010/10/05 00021 * Production release and review comments incorporated. 00022 * 00023 * Version 1.0.0 2010/09/20 00024 * Production release and review comments incorporated. 00025 * -------------------------------------------------------------------- */ 00026 00027 #include "arm_math.h" 00028 00058 static const q15_t sinTableQ15[259] = { 00059 0xfcdc, 0x0, 0x324, 0x648, 0x96b, 0xc8c, 0xfab, 0x12c8, 00060 0x15e2, 0x18f9, 0x1c0c, 0x1f1a, 0x2224, 0x2528, 0x2827, 0x2b1f, 00061 0x2e11, 0x30fc, 0x33df, 0x36ba, 0x398d, 0x3c57, 0x3f17, 0x41ce, 00062 0x447b, 0x471d, 0x49b4, 0x4c40, 0x4ec0, 0x5134, 0x539b, 0x55f6, 00063 0x5843, 0x5a82, 0x5cb4, 0x5ed7, 0x60ec, 0x62f2, 0x64e9, 0x66d0, 00064 0x68a7, 0x6a6e, 0x6c24, 0x6dca, 0x6f5f, 0x70e3, 0x7255, 0x73b6, 00065 0x7505, 0x7642, 0x776c, 0x7885, 0x798a, 0x7a7d, 0x7b5d, 0x7c2a, 00066 0x7ce4, 0x7d8a, 0x7e1e, 0x7e9d, 0x7f0a, 0x7f62, 0x7fa7, 0x7fd9, 00067 0x7ff6, 0x7fff, 0x7ff6, 0x7fd9, 0x7fa7, 0x7f62, 0x7f0a, 0x7e9d, 00068 0x7e1e, 0x7d8a, 0x7ce4, 0x7c2a, 0x7b5d, 0x7a7d, 0x798a, 0x7885, 00069 0x776c, 0x7642, 0x7505, 0x73b6, 0x7255, 0x70e3, 0x6f5f, 0x6dca, 00070 0x6c24, 0x6a6e, 0x68a7, 0x66d0, 0x64e9, 0x62f2, 0x60ec, 0x5ed7, 00071 0x5cb4, 0x5a82, 0x5843, 0x55f6, 0x539b, 0x5134, 0x4ec0, 0x4c40, 00072 0x49b4, 0x471d, 0x447b, 0x41ce, 0x3f17, 0x3c57, 0x398d, 0x36ba, 00073 0x33df, 0x30fc, 0x2e11, 0x2b1f, 0x2827, 0x2528, 0x2224, 0x1f1a, 00074 0x1c0c, 0x18f9, 0x15e2, 0x12c8, 0xfab, 0xc8c, 0x96b, 0x648, 00075 0x324, 0x0, 0xfcdc, 0xf9b8, 0xf695, 0xf374, 0xf055, 0xed38, 00076 0xea1e, 0xe707, 0xe3f4, 0xe0e6, 0xdddc, 0xdad8, 0xd7d9, 0xd4e1, 00077 0xd1ef, 0xcf04, 0xcc21, 0xc946, 0xc673, 0xc3a9, 0xc0e9, 0xbe32, 00078 0xbb85, 0xb8e3, 0xb64c, 0xb3c0, 0xb140, 0xaecc, 0xac65, 0xaa0a, 00079 0xa7bd, 0xa57e, 0xa34c, 0xa129, 0x9f14, 0x9d0e, 0x9b17, 0x9930, 00080 0x9759, 0x9592, 0x93dc, 0x9236, 0x90a1, 0x8f1d, 0x8dab, 0x8c4a, 00081 0x8afb, 0x89be, 0x8894, 0x877b, 0x8676, 0x8583, 0x84a3, 0x83d6, 00082 0x831c, 0x8276, 0x81e2, 0x8163, 0x80f6, 0x809e, 0x8059, 0x8027, 00083 0x800a, 0x8000, 0x800a, 0x8027, 0x8059, 0x809e, 0x80f6, 0x8163, 00084 0x81e2, 0x8276, 0x831c, 0x83d6, 0x84a3, 0x8583, 0x8676, 0x877b, 00085 0x8894, 0x89be, 0x8afb, 0x8c4a, 0x8dab, 0x8f1d, 0x90a1, 0x9236, 00086 0x93dc, 0x9592, 0x9759, 0x9930, 0x9b17, 0x9d0e, 0x9f14, 0xa129, 00087 0xa34c, 0xa57e, 0xa7bd, 0xaa0a, 0xac65, 0xaecc, 0xb140, 0xb3c0, 00088 0xb64c, 0xb8e3, 0xbb85, 0xbe32, 0xc0e9, 0xc3a9, 0xc673, 0xc946, 00089 0xcc21, 0xcf04, 0xd1ef, 0xd4e1, 0xd7d9, 0xdad8, 0xdddc, 0xe0e6, 00090 0xe3f4, 0xe707, 0xea1e, 0xed38, 0xf055, 0xf374, 0xf695, 0xf9b8, 00091 0xfcdc, 0x0, 0x324 00092 }; 00093 00094 00103 q15_t arm_sin_q15( 00104 q15_t x) 00105 { 00106 q31_t sinVal; /* Temporary variables output */ 00107 q15_t *tablePtr; /* Pointer to table */ 00108 q15_t fract, in, in2; /* Temporary variables for input, output */ 00109 q31_t wa, wb, wc, wd; /* Cubic interpolation coefficients */ 00110 q15_t a, b, c, d; /* Four nearest output values */ 00111 q15_t fractCube, fractSquare; /* Temporary values for fractional value */ 00112 q15_t oneBy6 = 0x1555; /* Fixed point value of 1/6 */ 00113 q15_t tableSpacing = TABLE_SPACING_Q15; /* Table spacing */ 00114 int32_t index; /* Index variable */ 00115 00116 in = x; 00117 00118 /* Calculate the nearest index */ 00119 index = (int32_t) in / tableSpacing; 00120 00121 /* Calculate the nearest value of input */ 00122 in2 = (q15_t) ((index) * tableSpacing); 00123 00124 /* Calculation of fractional value */ 00125 fract = (in - in2) << 8; 00126 00127 /* fractSquare = fract * fract */ 00128 fractSquare = (q15_t) ((fract * fract) >> 15); 00129 00130 /* fractCube = fract * fract * fract */ 00131 fractCube = (q15_t) ((fractSquare * fract) >> 15); 00132 00133 /* Initialise table pointer */ 00134 tablePtr = (q15_t *) & sinTableQ15[index]; 00135 00136 /* Cubic interpolation process */ 00137 /* Calculation of wa */ 00138 /* wa = -(oneBy6)*fractCube + (fractSquare >> 1u) - (0x2AAA)*fract; */ 00139 wa = (q31_t) oneBy6 *fractCube; 00140 wa += (q31_t) 0x2AAA * fract; 00141 wa = -(wa >> 15); 00142 wa += ((q31_t) fractSquare >> 1u); 00143 00144 /* Read first nearest value of output from the sin table */ 00145 a = *tablePtr++; 00146 00147 /* sinVal = a * wa */ 00148 sinVal = a * wa; 00149 00150 /* Calculation of wb */ 00151 wb = (((q31_t) fractCube >> 1u) - (q31_t) fractSquare) - 00152 (((q31_t) fract >> 1u) - 0x7FFF); 00153 00154 /* Read second nearest value of output from the sin table */ 00155 b = *tablePtr++; 00156 00157 /* sinVal += b*wb */ 00158 sinVal += b * wb; 00159 00160 00161 /* Calculation of wc */ 00162 wc = -(q31_t) fractCube + fractSquare; 00163 wc = (wc >> 1u) + fract; 00164 00165 /* Read third nearest value of output from the sin table */ 00166 c = *tablePtr++; 00167 00168 /* sinVal += c*wc */ 00169 sinVal += c * wc; 00170 00171 /* Calculation of wd */ 00172 /* wd = (oneBy6)*fractCube - (oneBy6)*fract; */ 00173 fractCube = fractCube - fract; 00174 wd = ((q15_t) (((q31_t) oneBy6 * fractCube) >> 15)); 00175 00176 /* Read fourth nearest value of output from the sin table */ 00177 d = *tablePtr++; 00178 00179 /* sinVal += d*wd; */ 00180 sinVal += d * wd; 00181 00182 /* Return the output value in 1.15(q15) format */ 00183 return ((q15_t) (sinVal >> 15u)); 00184 00185 } 00186  All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Defines Generated on Mon Nov 29 2010 17:19:57 for CMSIS DSP Software Library by  1.7.2