/**********************************************
         Adaptive Filter Program
        Coded for the ADSP21020 by 
 Eric Wigforss, Kevin Johns, John Siedlecki
   Digital Signal Processing Design Lab
	28 February 1995
***********************************************/

#include <21020.h>
#include <signal.h>
#include <macros.h>

volatile int in_port1  segment (hip_reg0);
volatile int in_port2  segment (hip_reg1);
volatile int out_port1 segment (hip_reg2);
volatile int out_port2 segment (hip_reg3);
volatile int control_0 segment (hip_reg4);

void process_input(int);
void timer_isr (int interrupt_number);
void irq2_interrupt(int sig_number);

float converge = 0.00005;
int old_u = 0;
int w = 1000;

void main(void)
{
    timer_set(6250000, 6250000);
    interrupt(SIG_IRQ3, process_input);
    interrupt(SIG_TMZ0, timer_isr);
    interrupt(SIG_IRQ2, irq2_interrupt);
    timer_on();

    set_flag(SET_FLAG1, CLR_FLAG);  /* turn off led 1 */
    set_flag(SET_FLAG2, CLR_FLAG);

    for(;;)                                     /* infinite loop */
        {
	poll_flag_in(READ_FLAG0, FLAG_IN_LO_TO_HI); /* wait for switch press  */
	set_flag(SET_FLAG1, SET_FLAG);                  /* turn on led 1            */
	converge = converge + 0.0005;
	poll_flag_in(READ_FLAG0, FLAG_IN_HI_TO_LO); /* wait for release             */
	set_flag(SET_FLAG1, CLR_FLAG);                  /* turn off led 1           */
        }
}

void timer_isr(int interrupt_number)
{
    set_flag(SET_FLAG1, TGL_FLAG);
}

void process_input(int sig_number)
{
    int d;
    int u;
    int e;
    int y;
    d = in_port1;  /* left input - summed - 100 Hz + 60 Hz*/
    u = in_port2;  /* right input - carrier - 60 Hz*/
    y = old_u / 1000 * w;
    e = d - y;
    w = w + (( (float) e / 130000.0) * ( (float) old_u / 130000.0) * converge); 
      if (u > 5000) set_flag(SET_FLAG2, SET_FLAG); 
      else set_flag(SET_FLAG2, CLR_FLAG);
   /*   w = 1; */
    out_port1 = e; /* left - filter */
    out_port2 = d; /* right - carrier */
    old_u = u;
}

void irq2_interrupt(int sig_number)
{
control_0 = 0x2400;
}