expiir.c

自己编了无限冲击响应滤波器

extern void initial(void);
extern void READAD7822(void);
extern void WRITEDAC08(void);
/***********************************************************************
** Main Function Program
***********************************************************************/
  #include "stdio.h"
  #include "math.h"
  #define pi 3.1415926 
  double a[4],b[4],x,y;
  int *px = (int*)0x3000;
  int *py = (int*)0x3200;
void main(void)
{
		
	int y_da;
	double w2,w1,w0,w3;	
	w3=w2=w1=w0=0.0;
	initial(); /* initialize C5402 DSP */       
    for ( ; ; )
	 {
	   READAD7822();
       x = *px;
       w3=x+2.6514*w2-2.3609*w1+0.7050*w0;	  //Fc=2000
	   y=0.0006*w3+0.0017*w2+0.0017*w1+0.0006*w0;   
       w0=w1;
       w1=w2;
       w2=w3;
       y_da = (int) y;
       *py =y_da;
       WRITEDAC08();
	 } 
}

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