#include?“DSP2833x_Device.h“?????//?DSP2833x?Headerfile?Include?File
#include?“DSP2833x_Examples.h“???//?DSP2833x?Examples?Include?File
#include??
//?Determine?when?the?shift?to?right?justify?the?data?takes?place
//?Only?one?of?these?should?be?defined?as?1.
//?The?other?two?should?be?defined?as?0.
#define?POST_SHIFT???0??//?Shift?results?after?the?entire?sample?table?is?full
#define?INLINE_SHIFT?1??//?Shift?results?as?the?data?is?taken?from?the?results?regsiter
#define?NO_SHIFT?????0??//?Do?not?shift?the?results

#define?pi?3.141593?//?float小數點后6位
#define?NL?256??//?NL為合成信號點數，與N的值必須是一致的，即NL=N
????int?N=NL;???//FFT點數

//?ADC?start?parameters
#if?（CPU_FRQ_150MHZ）?????//?Default?-?150?MHz?SYSCLKOUT
??#define?ADC_MODCLK?0x3?//?HSPCLK?=?SYSCLKOUT/2*ADC_MODCLK2?=?150/（2*3）???=?25.0?MHz
#endif
#if?（CPU_FRQ_100MHZ）
??#define?ADC_MODCLK?0x2?//?HSPCLK?=?SYSCLKOUT/2*ADC_MODCLK2?=?100/（2*2）???=?25.0?MHz
#endif
#define?ADC_CKPS???0x0???//?ADC?module?clock?=?HSPCLK/1??????=?25.5MHz/（1）???=?25.0?MHz
#define?ADC_SHCLK??0x1???//?S/H?width?in?ADC?module?periods??????????????????=?2?ADC?cycle
#define?AVG????????1000??//?Average?sample?limit
#define?ZOFFSET????0x00??//?Average?Zero?offset
#define?BUF_SIZE???512??//?Sample?buffer?size
/**************************************函數聲明************************************************/
void?scia_echoback_init（void）;??//聲明SCI-A工作方式和參數配置
void?scia_xmit（int?a）;??????????//聲明發送字節的函數
void?scia_msg（char?*msg）;???????//聲明發送數組的函數
/**********************************************************************************************/
//?Global?variable?for?this?example
Uint16?SampleTable[BUF_SIZE];
struct?Complex		//?定義復數結構體
{
???float?realimag;
};
struct?Complex?Wn;//定義旋轉因子
struct?Complex?Vn;//每一級第一個旋轉因子虛部為0，實部為1
struct?Complex?T;//存放旋轉因子與X（k+B）的乘積

//float?Realin[NL]={0};//?采樣輸入的實數
float?output[NL]={0};//?輸出的FFT幅值（復數的模）
struct?Complex?Sample[NL];//?采樣輸入的實數轉化為復數

struct?Complex?MUL（struct?Complex?astruct?Complex?b）//定義復乘
{
???struct?Complex?c;
???c.real=a.real*b.real-a.imag*b.imag;
???c.imag=a.real*b.imag+a.imag*b.real;
???return（c）;
}

void?MYFFT（struct?Complex?*xinint?N）//輸入為復數指針*xin，做N點FFT
{
???int?L=0;?//?級間運算層
???int?J=0;?//?級內運算層
???int?K=0KB=0;?//?蝶形運算層
???int?M=1Nn=0;//?N=2^M
???float?B=0;?//?蝶形運算兩輸入數據間隔
???/*?以下是為倒序新建的局部變量*/
???int?LH=0J2=0N1=0IK2=0;
???struct?Complex?T;
???/*以下是倒序*/
???LH=N/2;?//?LH=N/2
???J2=LH;
???N1=N-2;
???for（I=1;I<=N1;I++）
????{
?????if（I	?{
???????T=xin[I];
???????xin[I]=xin[J2];
???????xin[J2]=T;
	?}
	?K2=LH;
	?while（J2>=K2）
	??{
????????J2-=K2;
????????K2=K2/2;//?K2=K2/2
	??}
	??J2+=K2;
????}
???/*?以下為計算出M?*/
???Nn=N;
???while（Nn!=2）//?計算出N的以2為底數的冪M
???{
?????M++;
	?Nn=Nn/2;
???}

???/*?蝶形運算?*/
???for（L=1;L<=M;L++）??//?級間
	{
	??B=pow（2（L-1））;
??????Vn.real=1;
	??Vn.imag=0;
??????Wn.real=cos（pi/B）;
??????Wn.imag=-sin（pi/B）;
	??for（J=0;J	???{
		?for（K=J;K