// Copyright 2006 Yamane Akira
// Input Capture Test Sample Program
// Target : M48
// Crystal: 1.0000Mhz
// PB0->ICP1, measuring time from falling edge to falling edge
// Programmed by A. Yamane 2005 Sept.

#include <iom48v.h>
#include <macros.h>

  unsigned int cur_v, temp_v, value;

void port_init(void)
{
 PORTB = 0xFE; // PB0->icp1
 DDRB  = 0xFE;
 PORTC = 0x7F; 
 DDRC  = 0x7F;
 PORTD = 0xFF;
 DDRD  = 0xFF;
}

//TIMER1 initialize - prescale:8
// WGM: 0) Normal, TOP=0xFFFF
// clkio = 8us
// 
void timer1_init(void)
{
 TCCR1B = 0x00; //stop
 TCNT1H = 0xFF; //setup
 TCNT1L = 0x83;
 OCR1AH = 0x00;
 OCR1AL = 0x7D;
 OCR1BH = 0x00;
 OCR1BL = 0x7D;
 ICR1H  = 0x00;
 ICR1L  = 0x00;
 TCCR1A = 0x00;
 TCCR1B = 0x02; //start Timer, Prescaler 1/8, Input Capture Edge ICES1=0 
}

#pragma interrupt_handler timer1_capt_isr:11
void timer1_capt_isr(void)
{
    cur_v = ICR1L;
	cur_v |= (int)ICR1H << 8;	
	value = cur_v - temp_v;
	temp_v = cur_v;
	PORTD = ~(char)value;
	PORTC = ~(char)(value>>8);
}

#pragma interrupt_handler timer1_ovf_isr:14
void timer1_ovf_isr(void)
{
    temp_v = 0x0000;
}

//call this routine to initialize all peripherals
void init_devices(void)
{
 //stop errant interrupts until set up
 CLI(); //disable all interrupts
 port_init();
 timer1_init();

 MCUCR = 0x00;
 EICRA = 0x00; //extended ext ints
 EIMSK = 0x00;
 
 TIMSK0 = 0x00; //timer 0 interrupt sources
 TIMSK1 = 0x21; //timer 1 bit5 (ICIE1) is set, bit0(TOIE1) is set
 TIMSK2 = 0x00; //timer 2 interrupt sources
 
 PCMSK0 = 0x00; //pin change mask 0 
 PCMSK1 = 0x00; //pin change mask 1 
 PCMSK2 = 0x00; //pin change mask 2
 PCICR = 0x00; //pin change enable 
 PRR = 0x00; //power controller
 SEI(); //re-enable interrupts
 //all peripherals are now initialized
}

//
void main(void)
{
 init_devices();
   temp_v = 0x0000;
   cur_v = 0x0000;
   while(1)
    {
	}
}