//TMS320LF2407上实现快速傅里叶变换（FFT）
//FFT的程序代码
//(1)主程序
#include "f2407_c.h"
#include "math.h"
#define N 32 // FFT变换的点数
extern void fft(void);
extern void resave(void);
interrupt void phantom(void);
void sysinit(void);
extern int input[2*N]; // 输入数据的存储数组
int indati[N]={0};
// -----------------------------------------------------------------------------------
// 128 点 FFT所需的数据
// 采样函数:x=1/4+1/4cos(3*2*pi*f*t)+1/4cos(6*2*pi*f*t)+1/4cos(9*2*pi*f*t);
// f=50Hz
// -----------------------------------------------------------------------------------
/* int indatr[N]={16394,15871,14425,12398,10276 ,8584 ,7767 ,8088 ,9557 ,
11913 , 14660 ,17155 , 18724 , 18802 , 17044 , 13411 , 8197 , 1995 ,
-4389 ,-10071, -14231 , -16255 ,-15844, -13057 ,-8309 , -2296, 4125 ,
10079, 14819, 17843 , 18969, 18342 , 16394 ,13739 , 11055 , 8950
7848, 7921 , 9070 , 10961, 13110 , 14992 , 16159 , 16334 ,547,
13792 , 11675 , 9640 , 8197 , 7741, 8457, 10264 , 12815 , 15554 ,
17812 ,18939 , 18429 , 16034 , 11825 , 6203 , -156, -6405, -11662 ,
-15165 , -16394 , -15165 ,-11662 , -6405 , -156 , 6203 , 11825 , 16034,
18429, 18939 , 17812 , 15554 , 12815 ,10264 , 8457 , 7741 , 8197,
9640 , 11675, 13792, 15479 , 16334 , 16159, 14992 ,13110 , 10961 ,
9070 ,7921 , 7848 , 8950 , 11055 , 13739 , 16393 , 18342 , 18969 ,
17843 , 14819 , 10079 ,4125 , -2296 , -8309 , -13057 , -15844 , -16255 ,
-14231 , -10071 ,-4389 , 1995 , 8197 , 13411 , 17044 , 18802 , 18724 ,
17155 , 14660 , 11913 , 9557 ,8088 , 7767, 8584 , 10276 , 12398 ,
14425 , 15871 ,
};*/
// -----------------------------------------------------------------------------------
// 32点FFT所需的数据
// 采样函数:x=1/4+1/4cos(3*2*pi*f*t)+1/4cos(6*2*pi*f*t)+1/4cos(9*2*pi*f*t);
// f=50Hz ;pi=π;
// -----------------------------------------------------------------------------------
/* int indatr[N]={16384, 10270,9551 ,18713 , 8192 ,-14222,-8304,14810,16384,7843,13102 ,15469,8192,12807,
18418,-0156,-16384,-0156,-16384, -0156,18418,12807,8192,15469,13102,7843,16383,14810,
-8304,-14222,8192,18713,9551,10270,
};*/
int indatr[N]={0x07ff, 0x07ff,0x07ff,0x07ff,0x07ff,0x07ff,0x07ff,0x07ff,
0x07ff,0x07ff,0x07ff,0x07ff,0x07ff,0x07ff,0x07ff,0x07ff,0x0F801,
0x0F801,0x0F801,0x0F801,0x0F801,0x0F801,0x0F801,0x0F801,
0x0F801,0x0F801,0x0F801,0x0F801,0x0F801,0x0F801,0x0F801,
0x0F801,
};
// -----------------------------------------------------------------------------------
// 64点 FFT所需的数据
// 采样函数:x=1/4+1/4cos(3*2*pi*f*t)+1/4cos(6*2*pi*f*t)+1/4cos(9*2*pi*f*t);
// f=50Hz
// -----------------------------------------------------------------------------------
/* int indatr[N]={16384 , 14416, 10270, 7762, 9551 , 14651 , 18713, 17034, 8192 , -4387 ,-14222,-15834 ,-8304 ,4123 , 14810 ,18957 , 16384 , 1
// ---------------------------------------------------------------
// 128 点 FFT的sin 和 cos值存储表
// ---------------------------------------------------------------
/* const int sintab[N]={0x07fff,0x0,0x07fd9,0x0f9b9,0x07f62,0x0f375,0x07e9d,0x0ed38,
0x07d8a,0x0e708,0x07c2a,0x0e0e7,0x07a7d,0x0dad8,0x07885,0x0d4e1,
0x07642,0x0cf05,0x073b6,0x0c946,0x070e3,0x0c3aa,0x06dca,0x0be32,
0x06A6C,0x0B8E4,0x066CE,0x0B3C1,0x062F1,0x0AECD,0x05ED6,0x0AA0C,
0x05A81,0x0A57F,0x055F4,0x0A12A,0x05133,0x09D0F,0x04C3F,0x09932,
0x0471C,0x09594,0x041CD,0x09237,0x03C56,0x08F1F,0x036B9,0x08C4B,
0x030FB,0x089C0,0x02B1E,0x0877D,0x02527,0x08584,0x01F19,0x083D7,
0x018F8,0x08277,0x012C7,0x08164,0x00C8B,0x0809F,0x00647,0x08029,
0x00000,0x08001,0x0F9B9,0x08029,0x0F375,0x0809F,0x0ED39,0x08164,
0x0E708,0x08277,0x0E0E7,0x083D7,0x0DAD9,0x08584,0x0D4E2,0x0877D,
0x0CF05,0x089C0,0x0C947,0x08C4B,0x0C3AA,0x08F1F,0x0BE33,0x09237,
0x0B8E4,0x09594,0x0B3C1,0x09932,0x0AECD,0x09D0F,0x0AA0C,0x0A12A,
0x0A57F,0x0A57F,0x0A12A,0x0AA0C,0x09D0F,0x0AECD,0x09932,0x0B3C1,
0x09594,0x0B8E4,0x09237,0x0BE33,0x08F1F,0x0C3AA,0x08C4B,0x0C947,
0x089C0,0x0CF05,0x0877D,0x0D4E2,0x08584,0x0DAD9,0x083D7,0x0E0E7,
0x08277,0x0E708,0x08164,0x0ED39,0x0809F,0x0F375,0x08029,0x0F9B9
};*/
// ---------------------------------------------------------------
// 64点 FFT的sin 和 cos值存储表
// ---------------------------------------------------------------
/* const int sintab[N]={ 0x7FFF,0x0000,0x7F61 ,0xF375,0x7D89 ,0xE708 ,0x7A7C ,0xDAD9,0x7640,0xCF05 ,0x70E1 ,0xC3AA ,0x6A6C ,0xB8E4 ,0x62F1 ,0xAECD ,
0x5A81,0xA57F,0x5133,0x9D0F,0x471C ,0x9594, 0x3C56, 0x8F1F,
0x30FB,0x89C0 ,0x2527,0x8584 ,0x18F8 ,0x8277 ,0x0C8B ,0x809F,
0x0000 ,0x8001,0xF375,0x809F,0xE708 ,0x8277 ,0xDAD9 ,0x8584,
0xCF05 ,0x89C0 ,0xC3AA,0x8F1F,0xB8E4 ,0x9594 ,0xAECD ,0x9D0F,
0xA57F,0xA57F,0x9D0F,0xAECD,0x9594 ,0xB8E4 ,0x8F1F ,0xC3AA,
0x89C0,0xCF05,0x8584 ,0xDAD9 ,0x8277 ,0xE708 ,0x809F ,0xF375,};*/
// ---------------------------------------------------------------
// 32 点 FFT的sin 和 cos值存储表
// ---------------------------------------------------------------
const int sintab[N]={
0x7FFF,0x0000,0x7D89,0xE708,0x7640,0xCF05,0x6A6C,0xB8E4,
0x5A81,0xA57F,0x471C,0x9594,0x30FB,0x89C0,0x18F8,0x8277,
0x0000,0x8001,0xE708,0x8277,0xCF05,0x89C0,0xB8E4,0x9594,
0xA57F,0xA57F,0x9594,0xB8E4,0x89C0,0xCF05,0x8277,0xE708,
};
extern int table128[];
extern int nom; // 当nom=1时,FFT 需要归一化处理
main()
{ int i;
double x=0,y;
nom=1; // 需要归一化处理
sysinit();
for(i=0;i<=255;i++) input[i]=0; // 清除输入数据
resave(); // 把原始的输入数据反序排列
*PCDATDIR=(*PCDATDIR&0x0FF00)|0x01;
fft( ); // 进行FFT运算
*PCDATDIR=*PCDATDIR&0x0FF00;
}
void interrupt phantom(void)
{
return;
}
void sysinit(void)
{
*SCSR1=0x81FE;
*WDCR=0x0E8;
*IFR=0x0FF;
*IMR=0x0;
WSGR=0;
*MCRB=0;
*PCDATDIR=0x100;
}
void interrupt nothing()
{
return;
}
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