| /* ---------------------------------------------------------------------- |
| * Copyright (C) 2010-2014 ARM Limited. All rights reserved. |
| * |
| * $Date: 19. March 2015 |
| * $Revision: V.1.4.5 |
| * |
| * Project: CMSIS DSP Library |
| * Title: arm_sin_cos_q31.c |
| * |
| * Description: Cosine & Sine calculation for Q31 values. |
| * |
| * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * - Neither the name of ARM LIMITED nor the names of its contributors |
| * may be used to endorse or promote products derived from this |
| * software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
| * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| * POSSIBILITY OF SUCH DAMAGE. |
| * -------------------------------------------------------------------- */ |
| |
| #include "arm_math.h" |
| #include "arm_common_tables.h" |
| |
| /** |
| * @ingroup groupController |
| */ |
| |
| /** |
| * @addtogroup SinCos |
| * @{ |
| */ |
| |
| /** |
| * @brief Q31 sin_cos function. |
| * @param[in] theta scaled input value in degrees |
| * @param[out] *pSinVal points to the processed sine output. |
| * @param[out] *pCosVal points to the processed cosine output. |
| * @return none. |
| * |
| * The Q31 input value is in the range [-1 0.999999] and is mapped to a degree value in the range [-180 179]. |
| * |
| */ |
| |
| void arm_sin_cos_q31( |
| q31_t theta, |
| q31_t * pSinVal, |
| q31_t * pCosVal) |
| { |
| q31_t fract; /* Temporary variables for input, output */ |
| uint16_t indexS, indexC; /* Index variable */ |
| q31_t f1, f2, d1, d2; /* Two nearest output values */ |
| q31_t Dn, Df; |
| q63_t temp; |
| |
| /* Calculate the nearest index */ |
| indexS = (uint32_t)theta >> CONTROLLER_Q31_SHIFT; |
| indexC = (indexS + 128) & 0x1ff; |
| |
| /* Calculation of fractional value */ |
| fract = (theta - (indexS << CONTROLLER_Q31_SHIFT)) << 8; |
| |
| /* Read two nearest values of input value from the cos & sin tables */ |
| f1 = sinTable_q31[indexC+0]; |
| f2 = sinTable_q31[indexC+1]; |
| d1 = -sinTable_q31[indexS+0]; |
| d2 = -sinTable_q31[indexS+1]; |
| |
| Dn = 0x1921FB5; // delta between the two points (fixed), in this case 2*pi/FAST_MATH_TABLE_SIZE |
| Df = f2 - f1; // delta between the values of the functions |
| temp = Dn*((q63_t)d1 + d2); |
| temp = temp - ((q63_t)Df << 32); |
| temp = (q63_t)fract*(temp >> 31); |
| temp = temp + ((3*(q63_t)Df << 31) - (d2 + ((q63_t)d1 << 1))*Dn); |
| temp = (q63_t)fract*(temp >> 31); |
| temp = temp + (q63_t)d1*Dn; |
| temp = (q63_t)fract*(temp >> 31); |
| |
| /* Calculation of cosine value */ |
| *pCosVal = clip_q63_to_q31((temp >> 31) + (q63_t)f1); |
| |
| /* Read two nearest values of input value from the cos & sin tables */ |
| f1 = sinTable_q31[indexS+0]; |
| f2 = sinTable_q31[indexS+1]; |
| d1 = sinTable_q31[indexC+0]; |
| d2 = sinTable_q31[indexC+1]; |
| |
| Df = f2 - f1; // delta between the values of the functions |
| temp = Dn*((q63_t)d1 + d2); |
| temp = temp - ((q63_t)Df << 32); |
| temp = (q63_t)fract*(temp >> 31); |
| temp = temp + ((3*(q63_t)Df << 31) - (d2 + ((q63_t)d1 << 1))*Dn); |
| temp = (q63_t)fract*(temp >> 31); |
| temp = temp + (q63_t)d1*Dn; |
| temp = (q63_t)fract*(temp >> 31); |
| |
| /* Calculation of sine value */ |
| *pSinVal = clip_q63_to_q31((temp >> 31) + (q63_t)f1); |
| } |
| |
| /** |
| * @} end of SinCos group |
| */ |