/*IIR6BPC.C -REAL-TIME 6th-ORDER IIR BANDPASS FILTER*/
#include "aiccomc.c"     /*include AIC comm routines*/
#include "iir6coef.h"    /*coefficients file        */
float dly[stages][2] = {0};   /*delay samples       */
int AICSEC[4] = {0x162C,0x1,0x3872,0x67}; /*AIC data*/
int data_in, data_out;

float IIR(int *IO_in, int *IO_out, int n, int len)
{
 int i, loop = 0;
 float un, yn, input;
 while (loop < len)
 {
  asm("    IDLE   ");
  ++loop;
  input = *IO_in;   
  for (i = 0; i < n; i++)
   {
   un = input - b[i][0] * dly[i][0] - b[i][1] * dly[i][1];
   yn = a[i][2]*dly[i][1] + a[i][1]*dly[i][0] + a[i][0]*un;
   dly[i][1] = dly[i][0];
   dly[i][0] = un;
   input = yn;
   }
    *IO_out = yn;
 }
}

void c_int05()
{
  PBASE[0x48] = data_out << 2;
  data_in = PBASE[0x4C] << 16 >> 18;
}

main()
{
  #define length 345
  int *IO_OUTPUT, *IO_INPUT;
  IO_INPUT = &data_in;
  IO_OUTPUT = &data_out;
  AICSET_I();
  for (;;)  
   IIR((int *)IO_INPUT, (int *)IO_OUTPUT, stages, length);
}