Diff: TransformFunctions/arm_rfft_fast_init_f32.c

Revision:

0:3d9c67d97d6f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/TransformFunctions/arm_rfft_fast_init_f32.c	Mon Jul 28 15:03:15 2014 +0000
@@ -0,0 +1,149 @@
+/* ----------------------------------------------------------------------    
+* Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
+*    
+* $Date:        12. March 2014  
+* $Revision: 	V1.4.3  
+*    
+* Project: 	    CMSIS DSP Library    
+* Title:	    arm_cfft_init_f32.c   
+*    
+* Description:	Split Radix Decimation in Frequency CFFT Floating point processing 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 RealFFT   
+ * @{   
+ */
+
+/**   
+* @brief  Initialization function for the floating-point real FFT.  
+* @param[in,out] *S             points to an arm_rfft_fast_instance_f32 structure.
+* @param[in]     fftLen         length of the Real Sequence.  
+* @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  RFFT 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 RFFT/CIFFT process. Supported FFT Lengths are 16, 32, 64, 128, 256, 512, 1024, 2048, 4096.   
+* \par   
+* This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.   
+*/
+arm_status arm_rfft_fast_init_f32(
+  arm_rfft_fast_instance_f32 * S,
+  uint16_t fftLen)
+{
+  arm_cfft_instance_f32 * Sint;
+  /*  Initialise the default arm status */
+  arm_status status = ARM_MATH_SUCCESS;
+  /*  Initialise the FFT length */
+  Sint = &(S->Sint);
+  Sint->fftLen = fftLen/2;
+  S->fftLenRFFT = fftLen;
+
+  /*  Initializations of structure parameters depending on the FFT length */
+  switch (Sint->fftLen)
+  {
+  case 2048u:
+    /*  Initializations of structure parameters for 2048 point FFT */
+    /*  Initialise the bit reversal table length */
+    Sint->bitRevLength = ARMBITREVINDEXTABLE2048_TABLE_LENGTH;
+    /*  Initialise the bit reversal table pointer */
+    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable2048;
+    /*  Initialise the Twiddle coefficient pointers */
+		Sint->pTwiddle     = (float32_t *) twiddleCoef_2048;
+		S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_4096;
+    break;
+  case 1024u:
+    Sint->bitRevLength = ARMBITREVINDEXTABLE1024_TABLE_LENGTH;
+    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable1024;
+		Sint->pTwiddle     = (float32_t *) twiddleCoef_1024;
+		S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_2048;
+    break;
+  case 512u:
+    Sint->bitRevLength = ARMBITREVINDEXTABLE_512_TABLE_LENGTH;
+    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable512;
+		Sint->pTwiddle     = (float32_t *) twiddleCoef_512;
+		S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_1024;
+    break;
+  case 256u:
+    Sint->bitRevLength = ARMBITREVINDEXTABLE_256_TABLE_LENGTH;
+    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable256;
+		Sint->pTwiddle     = (float32_t *) twiddleCoef_256;
+		S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_512;
+    break;
+  case 128u:
+    Sint->bitRevLength = ARMBITREVINDEXTABLE_128_TABLE_LENGTH;
+    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable128;
+		Sint->pTwiddle     = (float32_t *) twiddleCoef_128;
+		S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_256;
+    break;
+  case 64u:
+    Sint->bitRevLength = ARMBITREVINDEXTABLE__64_TABLE_LENGTH;
+    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable64;
+		Sint->pTwiddle     = (float32_t *) twiddleCoef_64;
+		S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_128;
+    break;
+  case 32u:
+    Sint->bitRevLength = ARMBITREVINDEXTABLE__32_TABLE_LENGTH;
+    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable32;
+		Sint->pTwiddle     = (float32_t *) twiddleCoef_32;
+		S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_64;
+    break;
+  case 16u:
+    Sint->bitRevLength = ARMBITREVINDEXTABLE__16_TABLE_LENGTH;
+    Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable16;
+		Sint->pTwiddle     = (float32_t *) twiddleCoef_16;
+		S->pTwiddleRFFT    = (float32_t *) twiddleCoef_rfft_32;
+    break;
+  default:
+    /*  Reporting argument error if fftSize is not valid value */
+    status = ARM_MATH_ARGUMENT_ERROR;
+    break;
+  }
+
+  return (status);
+}
+
+/**   
+ * @} end of RealFFT group   
+ */