/* ======================================================================= */
/* DSP_fft32x32s.h -- 32x32s Mixed Radix FFT                               */
/*                    Intrinsic C Implementation                           */
/*                                                                         */
/* Rev 0.0.1                                                               */
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/* Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/  */ 
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/* ======================================================================= */

#ifndef DSP_FFT32X32S_H_
#define DSP_FFT32X32S_H_ 1

#ifndef __TI_COMPILER_VERSION__           // for non TI compiler
#include "assert.h"                       // intrinsics prototypes
#include "C6xSimulator.h"                 // intrinsics prototypes
#include "C6xSimulator_type_modifiers.h"  // define/undefine typing keywords
#endif

/** @ingroup FFT */
/* @{ */

/** @defgroup  DSP_fft32x32s */
/** @ingroup DSP_fft32x32s */
/* @{ */

/**
 *      This routine computes an extended precision complex 
 *      forward mixed radix FFT with scaling, rounding and 
 *      digit reversal. Input data x[ ], output data y[ ],
 *      and coefficients w[ ] are 32-bit. The output is returned 
 *      in the separate array y[ ] in normal order. Each complex 
 *      value is stored with interleaved real and imaginary parts.
 *
 *          @param  ptr_w   =  input twiddle factors    
 *          @param  npoints =  number of points         
 *          @param  ptr_x   =  transformed data reversed
 *          @param  ptr_y   =  linear transformed data  
 *
 * @par Algorithm:
 * DSP_fft32x32s_cn.c is the natural C equivalent of the optimized
 * intrinsic C code without restrictions. Note that the intrinsic
 * C code is optimized and restrictions may apply.  
 * 
 * @par Assumptions:
 *     In-place computation is not allowed. <BR>                             
 *     Size of FFT, nx, must be power of 2 and 16<=nx<=65536. <BR>                                 
 *     The arrays for the complex input data x[], complex output data y[]
 *        and twiddle factor w[] must be double word aligned. <BR>
 *     The input and output data are complex, with the real/imaginary 
 *        components stored in adjacent locations in the array.  The real
 *        components are stored at even array indices, and the imaginary 
 *        components are stored at odd array indices. <BR>                    
 *     Allowed maximum absolute value of input is 2^(32 - (log2(nx)-ceil[log4(nx)-1])). <BR>
 *
 * @par Implementation Notes:
 *     Scaling is performed at each stage by shifting the results right by 1,
 *        preventing overflow. <BR>
 *
 * @b Endian Support: The code supports both big and little endian modes. <BR> 
 * @b Interruptibility: The code is interruptible. <BR>
 *
 */

void DSP_fft32x32s (
    const int * restrict ptr_w,
    int npoints,
    int * restrict ptr_x,
    int * restrict ptr_y
);

#endif

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/*  End of file:  DSP_fft32x32s.h                                           */
/* ------------------------------------------------------------------------ */
/*            Copyright (c) 2011 Texas Instruments, Incorporated.           */
/*                           All Rights Reserved.                           */
/* ======================================================================== */