输入的input[N]图形如下，inputFFT为FFT Magnitude下的图形：
下图为magTest[ ]的64点与128点时图形，个人感觉不对，应该要同inputFFT一样才对啊，是不是哪里配错了：
源码如下：
#include "DSP28x_Project.h" // Device Headerfile and Examples Include File
#include <fft.h>
#include"math.h"
// Prototype statements for functions found within this file.
interrupt void adc_isr(void);
void Adc_Config(void);
// Global variables used in this example:
Uint16 LoopCount;
#if 0
Uint16 ConversionCount;
Uint16 Voltage1[10];
Uint16 Voltage2[10];
#endif
#define PI 3.1415926
#define N 128
long ipcb[N+2];
long mag[N/2+1];
long magTest[N/2+1];
#pragma DATA_SECTION(ipcb, "FFTipcb");
#pragma DATA_SECTION(mag, "FFTmag");
RFFT32 fft=RFFT32_128P_DEFAULTS;
RFFT32_ACQ acq=FFTRACQ_DEFAULTS;
#if 1
unsigned int input[N]=
{
0x000,0x00b,0x02c,0x062,0x0ac,0x109,0x176,0x1f1,0x307,0x39b,
0x432,0x4c7,0x558,0x5e2,0x661,0x6d4,0x736,0x787,0x7c4,0x7ec,
0x7fe,0x7ec,0x7c4,0x787,0x736,0x6d4,0x661,0x5e2,0x558,0x4c7,
0x432,0x39b,0x307,0x1f1,0x176,0x109,0x0ac,0x062,0x02c,0x00b,
0x000,0x00b,0x02c,0x062,0x0ac,0x109,0x176,0x1f1,0x307,0x39b,
0x432,0x4c7,0x558,0x5e2,0x661,0x6d4,0x736,0x787,0x7c4,0x7ec,
0x7fe,0x7ec,0x7c4,0x787,0x736,0x6d4,0x661,0x5e2,0x558,0x4c7,
0x432,0x39b,0x307,0x1f1,0x176,0x109,0x0ac,0x062,0x02c,0x00b,
0x000,0x00b,0x02c,0x062,0x0ac,0x109,0x176,0x1f1,0x307,0x39b,
0x432,0x4c7,0x558,0x5e2,0x661,0x6d4,0x736,0x787,0x7c4,0x7ec,
0x7fe,0x7ec,0x7c4,0x787,0x736,0x6d4,0x661,0x5e2,0x558,0x4c7,
0x432,0x39b,0x307,0x1f1,0x176,0x109,0x0ac,0x062,0x02c,0x00b,
0x000,0x00b,0x02c,0x062,0x0ac,0x109,0x176,0x1f1
};
#endif
main()
{
int i;
unsigned int *pInput;
pInput=input;
// Step 1. Initialize System Control:
// PLL, WatchDog, enable Peripheral Clocks
// This example function is found in the DSP2803x_SysCtrl.c file.
InitSysCtrl();
// Step 2. Initialize GPIO:
// This example function is found in the DSP2802x_Gpio.c file and
// illustrates how to set the GPIO to it's default state.
// InitGpio(); // Skipped for this example
// Step 3. Clear all interrupts and initialize PIE vector table:
// Disable CPU interrupts
DINT;
// Initialize the PIE control registers to their default state.
// The default state is all PIE interrupts disabled and flags
// are cleared.
// This function is found in the DSP2802x_PieCtrl.c file.
InitPieCtrl();
/* Initialize acquisition module */
acq.buffptr=ipcb;
acq.tempptr=ipcb;
acq.size=N;
acq.count=N;
acq.acqflag=1;
/* Initialize FFT module */
fft.ipcbptr=ipcb;
fft.magptr=mag;
// fft.winptr=(long *)win;
fft.init(&fft);
// Disable CPU interrupts and clear all CPU interrupt flags:
IER = 0x0000;
IFR = 0x0000;
// This function is found in DSP2802x_PieVect.c.
InitPieVectTable();
for(;;)
{
LoopCount++;
for(i=0;i<N;i++)
{
acq.input=((unsigned long)pInput[i])<<16; acq.update(&acq);
}
if (acq.acqflag==0) // If the samples are acquired
{
fft.calc(&fft);
fft.split(&fft);
fft.mag(&fft);
acq.acqflag=1; // Enable the next acquisition
for(i=0;i<N/2+1;i++)
{
magTest[i]=sqrt(mag[i]);
}
}
}
}