fir_c_extern_float.c

C6000DSP的C语言程序示例 一共有3个 内容不错

//#pragma DATA_SECTION(R_in, "mydata");  /* Place data in internal memory */
//#pragma DATA_SECTION(h, "mydata");     /* Place data in internal memory */

#define f0 0.078125
#define mul 2

float h[]=       /* Impulse response of FIR filter. Taken from fir_coef.txt */
{
	-0.0001,0.0003,0.0004,0.0002,-0.0002,-0.0005,-0.0004,0.0001,
	0.0006,0.0006,0.0001,-0.0006,-0.0010,-0.0005,0.0005,0.0013,
	0.0010,-0.0002,-0.0016,-0.0017,-0.0003,0.0016,0.0025,0.0012,
	-0.0013,-0.0032,-0.0025,0.0006,0.0036,0.0039,0.0007,-0.0036,
	-0.0054,-0.0027,0.0029,0.0068,0.0052,-0.0012,-0.0076,-0.0081,
	-0.0015,0.0074,0.0112,0.0055,-0.0059,-0.0139,-0.0108,0.0026,
	0.0159,0.0173,0.0033,-0.0165,-0.0254,-0.0129,0.0145,0.0355,
	0.0291,-0.0075,-0.0507,-0.0623,-0.0141,0.0897,0.2093,0.2890,
	0.2890,0.2093,0.0897,-0.0141,-0.0623,-0.0507,-0.0075,0.0291,
	0.0355,0.0145,-0.0129,-0.0254,-0.0165,0.0033,0.0173,0.0159,
	0.0026,-0.0108,-0.0139,-0.0059,0.0055,0.0112,0.0074,-0.0015,
	-0.0081,-0.0076,-0.0012,0.0052,0.0068,0.0029,-0.0027,-0.0054,
	-0.0036,0.0007,0.0039,0.0036,0.0006,-0.0025,-0.0032,-0.0013,
	0.0012,0.0025,0.0016,-0.0003,-0.0017,-0.0016,-0.0002,0.0010,
	0.0013,0.0005,-0.0005,-0.0010,-0.0006,0.0001,0.0006,0.0006,
	0.0001,-0.0004,-0.0005,-0.0002,0.0002,0.0004,0.0003,-0.0001

};

//#pragma CODE_SECTION (fir_filter, "mycode") /* Put routine in internal memory. */


void fir_filter ()
{
	int i,k;
	float acc[256]=0;
	float prod,data;
    float R_in[128]=0; /* Input samples R_in[0] most recent, R_in[127] oldest */

                   	/* Zero accumulator */
	for (k = 0 ;k < 256 ;k++)
	{
 	  data= 255*sin(2*3.14*k*f0*mul);  
	  for(i=127; i>0; i--)
	  {
	  	R_in[i]=R_in[i-1];
	  }
	  R_in[0] = data;
	  for (i=0; i<128; i++)         	/* 128 taps */
	  {   
	    prod = (h[i]*R_in[i]);  
		acc[k]= acc[k] + prod;           
	  }                             
	}
//	return (acc);

}