expfir.c

有限冲击响应滤波器

extern void initial(void);
extern void READAD7822(void);
extern void WRITEDAC08(void);
extern int  fir(int *x,int *h,int *r,unsigned int NX);
/***********************************************************************
** Main Function Program
***********************************************************************/
  #include "stdio.h"
  #include "math.h"
  #include "fird2000.h"
  #define pi 3.1415927
  #define  NX  35
  	int *px = (int*)0x3000;
	int *py = (int*)0x3200; 
  int r=0,i,datam,var=0;
  int buffer[256]; 
   main ()
  {
    initial(); /* initialize C5402 DSP */  		
    for (; ; )
     {	
	  READAD7822();
	  x[0]=*px;
   	  fir(&x[0],&h[0],&r,NX);            //调用滤波函数
   	  
   	  datam=r>>8;
   	  for (i = NX-1; i > 0; i--)  
   	  x[i] = x[i-1];                    //通过滤波器
   	  if (var==255) var=0;
   	  else var++;
   	  buffer[var]=r;
   	  *py = (int)(r>>1);               //输出
   	  WRITEDAC08();	
     }				
}


/***********************************************************************
** End of File –– ExpFIR.c
***********************************************************************/