main.c

MICROCHIP的DSPIC系列的30F6014单片机的32点FFT计算

#include <p30Fxxxx.h>
#include <dsp.h>
//#include "fft.h"

/* Device configuration register macros for building the hex file */
_FOSC(CSW_FSCM_OFF & XT_PLL8);          /* XT with 8xPLL oscillator, Failsafe clock off */
_FWDT(WDT_OFF);                         /* Watchdog timer disabled */
_FBORPOR(PBOR_OFF & MCLR_EN);           /* Brown-out reset disabled, MCLR reset enabled */
_FGS(CODE_PROT_OFF);                    /* Code protect disabled */


//


#define FFT_BLOCK_LENGTH	32     /* = Number of frequency points in the FFT */
#define LOG2_BLOCK_LENGTH 	5	/* = Number of "Butterfly" Stages in FFT processing */
#define SAMPLING_RATE		10000	/* = Rate at which input signal was sampled */

/* Extern definitions */
extern void SquareMagnitudeCplx(int, fractcomplex*, fractional*); /*This function computes the */
                                        /* squared magnitude of elements in a complex vector */


extern fractcomplex sigCmpx[FFT_BLOCK_LENGTH] 		/* Typically, the input signal to an FFT  */
__attribute__ ((section (".ydata, data, ymemory"), 	/* routine is a complex array containing samples */
aligned (FFT_BLOCK_LENGTH * 2 *2)));      		/* of an input signal. For this example, */
							/* we will provide the input signal in an */
							/* array declared in Y-data space. */
/* Global Definitions */
#ifndef FFTTWIDCOEFFS_IN_PROGMEM
fractcomplex twiddleFactors[FFT_BLOCK_LENGTH/2] 	/* Declare Twiddle Factor array in X-space*/
__attribute__ ((section (".xbss, bss, xmemory"), aligned (FFT_BLOCK_LENGTH*2)));
#else
extern const fractcomplex twiddleFactors[FFT_BLOCK_LENGTH/2]	/* Twiddle Factor array in Program memory */
__attribute__ ((space(auto_psv), aligned (FFT_BLOCK_LENGTH*2)));
#endif

int	peakFrequencyBin = 0;				/* Declare post-FFT variables to compute the */
unsigned long peakFrequency = 0;			/* frequency of the largest spectral component */

int main(void)
{
	/* Generate TwiddleFactor Coefficients */
	TwidFactorInit (LOG2_BLOCK_LENGTH, &twiddleFactors[0], 0);	/* We need to do this only once at start-up */
}