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Diffstat (limited to 'apps/mathlib/CMSIS/DSP_Lib/Source/TransformFunctions/arm_cfft_radix4_init_q15.c')
-rw-r--r-- | apps/mathlib/CMSIS/DSP_Lib/Source/TransformFunctions/arm_cfft_radix4_init_q15.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/apps/mathlib/CMSIS/DSP_Lib/Source/TransformFunctions/arm_cfft_radix4_init_q15.c b/apps/mathlib/CMSIS/DSP_Lib/Source/TransformFunctions/arm_cfft_radix4_init_q15.c new file mode 100644 index 000000000..5ace3483d --- /dev/null +++ b/apps/mathlib/CMSIS/DSP_Lib/Source/TransformFunctions/arm_cfft_radix4_init_q15.c @@ -0,0 +1,149 @@ +/* ----------------------------------------------------------------------
+* Copyright (C) 2010 ARM Limited. All rights reserved.
+*
+* $Date: 15. February 2012
+* $Revision: V1.1.0
+*
+* Project: CMSIS DSP Library
+* Title: arm_cfft_radix4_init_q15.c
+*
+* Description: Radix-4 Decimation in Frequency Q15 FFT & IFFT initialization function
+*
+* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
+*
+* Version 1.1.0 2012/02/15
+* Updated with more optimizations, bug fixes and minor API changes.
+*
+* Version 1.0.10 2011/7/15
+* Big Endian support added and Merged M0 and M3/M4 Source code.
+*
+* Version 1.0.3 2010/11/29
+* Re-organized the CMSIS folders and updated documentation.
+*
+* Version 1.0.2 2010/11/11
+* Documentation updated.
+*
+* Version 1.0.1 2010/10/05
+* Production release and review comments incorporated.
+*
+* Version 1.0.0 2010/09/20
+* Production release and review comments incorporated.
+*
+* Version 0.0.5 2010/04/26
+* incorporated review comments and updated with latest CMSIS layer
+*
+* Version 0.0.3 2010/03/10
+* Initial version
+* -------------------------------------------------------------------- */
+
+#include "arm_math.h"
+#include "arm_common_tables.h"
+
+/**
+ * @ingroup groupTransforms
+ */
+
+
+/**
+ * @addtogroup Radix4_CFFT_CIFFT
+ * @{
+ */
+
+
+/**
+* @brief Initialization function for the Q15 CFFT/CIFFT.
+* @param[in,out] *S points to an instance of the Q15 CFFT/CIFFT structure.
+* @param[in] fftLen length of the FFT.
+* @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform.
+* @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output.
+* @return The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if <code>fftLen</code> is not a supported value.
+*
+* \par Description:
+* \par
+* The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
+* Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated
+* \par
+* The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
+* Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
+* \par
+* The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.
+* \par
+* This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
+*/
+
+arm_status arm_cfft_radix4_init_q15(
+ arm_cfft_radix4_instance_q15 * S,
+ uint16_t fftLen,
+ uint8_t ifftFlag,
+ uint8_t bitReverseFlag)
+{
+ /* Initialise the default arm status */
+ arm_status status = ARM_MATH_SUCCESS;
+ /* Initialise the FFT length */
+ S->fftLen = fftLen;
+ /* Initialise the Twiddle coefficient pointer */
+ S->pTwiddle = (q15_t *) twiddleCoefQ15;
+ /* Initialise the Flag for selection of CFFT or CIFFT */
+ S->ifftFlag = ifftFlag;
+ /* Initialise the Flag for calculation Bit reversal or not */
+ S->bitReverseFlag = bitReverseFlag;
+
+ /* Initializations of structure parameters depending on the FFT length */
+ switch (S->fftLen)
+ {
+ case 4096u:
+ /* Initializations of structure parameters for 4096 point FFT */
+
+ /* Initialise the twiddle coef modifier value */
+ S->twidCoefModifier = 1u;
+ /* Initialise the bit reversal table modifier */
+ S->bitRevFactor = 1u;
+ /* Initialise the bit reversal table pointer */
+ S->pBitRevTable = (uint16_t *) armBitRevTable;
+
+ break;
+
+ case 1024u:
+ /* Initializations of structure parameters for 1024 point FFT */
+ S->twidCoefModifier = 4u;
+ S->bitRevFactor = 4u;
+ S->pBitRevTable = (uint16_t *) & armBitRevTable[3];
+
+ break;
+
+ case 256u:
+ /* Initializations of structure parameters for 256 point FFT */
+ S->twidCoefModifier = 16u;
+ S->bitRevFactor = 16u;
+ S->pBitRevTable = (uint16_t *) & armBitRevTable[15];
+
+ break;
+
+ case 64u:
+ /* Initializations of structure parameters for 64 point FFT */
+ S->twidCoefModifier = 64u;
+ S->bitRevFactor = 64u;
+ S->pBitRevTable = (uint16_t *) & armBitRevTable[63];
+
+ break;
+
+ case 16u:
+ /* Initializations of structure parameters for 16 point FFT */
+ S->twidCoefModifier = 256u;
+ S->bitRevFactor = 256u;
+ S->pBitRevTable = (uint16_t *) & armBitRevTable[255];
+
+ break;
+
+ default:
+ /* Reporting argument error if fftSize is not valid value */
+ status = ARM_MATH_ARGUMENT_ERROR;
+ break;
+ }
+
+ return (status);
+}
+
+/**
+ * @} end of Radix4_CFFT_CIFFT group
+ */
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