//FINAL EXAM A1
#include <mc9s12c32.h>

unsigned int dummyread, count = 0;
unsigned int t1, t2;

#pragma interrupt_handler tc0_isr
void tc0_isr()
{
   dummyread = TC0;
   t1 = TCNT;
   count++;
}

#pragma interrupt_handler tc1_isr
void tc1_isr()
{
   dummyread = TC1;
   t2 = TCNT;
   count++;
}

void main()
{
  unsigned float t;

  TSCR1=0x90; // enable timer and allow fast flag clear
  TIOS = 0xfc; // set tco and tc1 to input compare
  DDRT = ~0x03; // set pt0 and pt1 as input capture
  TCTL4 = 0x05; // pt0 and pt1 rising edge capture 0000.0101

  dummyread = TC0;
  dummyread = TC1;

  INTER_ON(); // globally interupt enable

  *(void (**)()) 0x0fee = tc0_isr;
  *(void (**)()) 0x0fec = tc1_isr;
  INTR_ON(); // globally enable interupts
  TIE = 0x03; // enable timer interupt tco and tc1

  while(1)
  {
      while(count < 2);
	  count = 0;
	  if(t2 > t1) t = t2 - t1;
	  else t = 0xffff - t1 + t2 + 1;

	  t = 1000000 / t;

  // math to convert 1 foot per X cycles to X feet per 1 second

  // 1 foot 10,000,000 cycles 1,000 feet
  // -------------- * ------------------ = ------------
  // 10,000 cycles 1 second 1 second

  printf("speed = %d\n", t);
  }
}