有没有大佬，能帮我解释一下这段程序，这是IIR数字滤波器的程序，刚接触，不太懂。

#define PI 3.1415926

#include <math.h>

#include <stdio.h>

#include "tms320.h"

#include "dsplib.h"

#define NX 200

#define NBIQ 6

DATA x[NX];

#pragma DATA_SECTION(h,".coeffs")

DATAh[5*NBIQ]={5771,0,0,8192,-7727,11661,4192,9309,8192,-17462,12022,4576,8906,8192,-17061,12641,5232,8291,8192,-16448,13535,6182,7717,8192,-15877,14722,7443,7374,8192,-15538

};

#pragma DATA_SECTION(dbuffer,".dbuffer")

DATA dbuffer[2*NBIQ];

DATA *dp = dbuffer;

DATA r[NX];

short i;

void main()

{ for (i=0;i<NX;i++) r[ i] =0;

            {x[ i]=(short)((sin(PI*2000*i/22000)+sin(PI*10000*i/22000)+sin(PI*12000*i/22000)+sin(PI*20000*i/22000))*32768/4);}
iircas5(x, h, r, dp, NBIQ, NX);

   while(1);

}