Diff: TransformFunctions/arm_cfft_radix2_init_f32.c

Revision:

0:3d9c67d97d6f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TransformFunctions/arm_cfft_radix2_init_f32.c	Mon Jul 28 15:03:15 2014 +0000
@@ -0,0 +1,205 @@
+/* ----------------------------------------------------------------------   
+* Copyright (C) 2010-2014 ARM Limited. All rights reserved.   
+*   
+* $Date:        12. March 2014  
+* $Revision: 	V1.4.3  
+*   
+* Project: 	    CMSIS DSP Library   
+* Title:	    arm_cfft_radix4_init_f32.c   
+*   
+* Description:	Radix-4 Decimation in Frequency Floating-point CFFT & CIFFT Initialization function   
+*   
+* 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 groupTransforms   
+ */
+
+/**   
+ * @addtogroup ComplexFFT   
+ * @{   
+ */
+
+/**   
+* @brief  Initialization function for the floating-point CFFT/CIFFT.  
+* @deprecated Do not use this function.  It has been superceded by \ref arm_cfft_f32 and will be removed
+* in the future.
+* @param[in,out] *S             points to an instance of the floating-point 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_radix2_init_f32(
+  arm_cfft_radix2_instance_f32 * 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 = (float32_t *) twiddleCoef;
+
+  /*  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;
+    /*  Initialise the 1/fftLen Value */
+    S->onebyfftLen = 0.000244140625;
+    break;
+
+  case 2048u:
+    /*  Initializations of structure parameters for 2048 point FFT */
+
+    /*  Initialise the twiddle coef modifier value */
+    S->twidCoefModifier = 2u;
+    /*  Initialise the bit reversal table modifier */
+    S->bitRevFactor = 2u;
+    /*  Initialise the bit reversal table pointer */
+    S->pBitRevTable = (uint16_t *) & armBitRevTable[1];
+    /*  Initialise the 1/fftLen Value */
+    S->onebyfftLen = 0.00048828125;
+    break;
+
+  case 1024u:
+    /*  Initializations of structure parameters for 1024 point FFT */
+
+    /*  Initialise the twiddle coef modifier value */
+    S->twidCoefModifier = 4u;
+    /*  Initialise the bit reversal table modifier */
+    S->bitRevFactor = 4u;
+    /*  Initialise the bit reversal table pointer */
+    S->pBitRevTable = (uint16_t *) & armBitRevTable[3];
+    /*  Initialise the 1/fftLen Value */
+    S->onebyfftLen = 0.0009765625f;
+    break;
+
+  case 512u:
+    /*  Initializations of structure parameters for 512 point FFT */
+
+    /*  Initialise the twiddle coef modifier value */
+    S->twidCoefModifier = 8u;
+    /*  Initialise the bit reversal table modifier */
+    S->bitRevFactor = 8u;
+    /*  Initialise the bit reversal table pointer */
+    S->pBitRevTable = (uint16_t *) & armBitRevTable[7];
+    /*  Initialise the 1/fftLen Value */
+    S->onebyfftLen = 0.001953125;
+    break;
+
+  case 256u:
+    /*  Initializations of structure parameters for 256 point FFT */
+    S->twidCoefModifier = 16u;
+    S->bitRevFactor = 16u;
+    S->pBitRevTable = (uint16_t *) & armBitRevTable[15];
+    S->onebyfftLen = 0.00390625f;
+    break;
+
+  case 128u:
+    /*  Initializations of structure parameters for 128 point FFT */
+    S->twidCoefModifier = 32u;
+    S->bitRevFactor = 32u;
+    S->pBitRevTable = (uint16_t *) & armBitRevTable[31];
+    S->onebyfftLen = 0.0078125;
+    break;
+
+  case 64u:
+    /*  Initializations of structure parameters for 64 point FFT */
+    S->twidCoefModifier = 64u;
+    S->bitRevFactor = 64u;
+    S->pBitRevTable = (uint16_t *) & armBitRevTable[63];
+    S->onebyfftLen = 0.015625f;
+    break;
+
+  case 32u:
+    /*  Initializations of structure parameters for 64 point FFT */
+    S->twidCoefModifier = 128u;
+    S->bitRevFactor = 128u;
+    S->pBitRevTable = (uint16_t *) & armBitRevTable[127];
+    S->onebyfftLen = 0.03125;
+    break;
+
+  case 16u:
+    /*  Initializations of structure parameters for 16 point FFT */
+    S->twidCoefModifier = 256u;
+    S->bitRevFactor = 256u;
+    S->pBitRevTable = (uint16_t *) & armBitRevTable[255];
+    S->onebyfftLen = 0.0625f;
+    break;
+
+
+  default:
+    /*  Reporting argument error if fftSize is not valid value */
+    status = ARM_MATH_ARGUMENT_ERROR;
+    break;
+  }
+
+  return (status);
+}
+
+/**   
+ * @} end of ComplexFFT group   
+ */