diff options
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_sin_q31.c')
-rw-r--r-- | Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_sin_q31.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_sin_q31.c b/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_sin_q31.c new file mode 100644 index 0000000..849cc11 --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/FastMathFunctions/arm_sin_q31.c @@ -0,0 +1,77 @@ +/* ----------------------------------------------------------------------
+ * Project: CMSIS DSP Library
+ * Title: arm_sin_q31.c
+ * Description: Fast sine calculation for Q31 values
+ *
+ * $Date: 18. March 2019
+ * $Revision: V1.6.0
+ *
+ * Target Processor: Cortex-M cores
+ * -------------------------------------------------------------------- */
+/*
+ * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the License); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an AS IS BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "arm_math.h"
+#include "arm_common_tables.h"
+
+/**
+ @ingroup groupFastMath
+ */
+
+/**
+ @addtogroup sin
+ @{
+ */
+
+/**
+ @brief Fast approximation to the trigonometric sine function for Q31 data.
+ @param[in] x Scaled input value in radians
+ @return sin(x)
+
+ The Q31 input value is in the range [0 +0.9999] and is mapped to a radian value in the range [0 2*PI).
+ */
+
+q31_t arm_sin_q31(
+ q31_t x)
+{
+ q31_t sinVal; /* Temporary variables for input, output */
+ int32_t index; /* Index variable */
+ q31_t a, b; /* Two nearest output values */
+ q31_t fract; /* Temporary values for fractional values */
+
+ /* Calculate the nearest index */
+ index = (uint32_t)x >> FAST_MATH_Q31_SHIFT;
+
+ /* Calculation of fractional value */
+ fract = (x - (index << FAST_MATH_Q31_SHIFT)) << 9;
+
+ /* Read two nearest values of input value from the sin table */
+ a = sinTable_q31[index];
+ b = sinTable_q31[index+1];
+
+ /* Linear interpolation process */
+ sinVal = (q63_t) (0x80000000 - fract) * a >> 32;
+ sinVal = (q31_t) ((((q63_t) sinVal << 32) + ((q63_t) fract * b)) >> 32);
+
+ /* Return output value */
+ return (sinVal << 1);
+}
+
+/**
+ @} end of sin group
+ */
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