// Copyright 2006 Yamane Akira
//ICC-AVR application builder : 2005/09/23 14:30:07
// Target : M48
// Crystal: 1.0000Mhz

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

  unsigned char row_data, col_data, stage;

void port_init(void)
{
 PORTB = 0x0F;
 DDRB  = 0xF0;
 PORTC = 0x7F; 
 DDRC  = 0x7F;
 PORTD = 0xFF;
 DDRD  = 0xFF;
}

//TIMER0 initialize - prescale:256
// WGM: Normal
// desired value: 10mSec
// actual value:  9.984mSec (0.2%)
void timer0_init(void)
{
 TCCR0B = 0x00; //stop
 TCNT0 = 0xD9; //set count
 TCCR0A = 0x00; 
 TCCR0B = 0x00; //stop timer
}

#pragma interrupt_handler timer0_ovf_isr:17
void timer0_ovf_isr(void)
{
    TCNT0 = 0xD9; //set count
    TCCR0B = 0x04; //start timer	
   if (stage == 0x00)
      row_data_r();
	  else if (stage == 0x01)
	     col_data_r();
		 else if (stage == 0x02)
		    sw_off_chk();
	else stage = 0xFF;
}

unsigned char swin2hex(unsigned char indata)
    {
	 unsigned char value;
	   switch (indata)
	   {
	     case 0b11101110: 
		     value = 0x00;
		     break;
	     case 0b11101101: 
		     value = 0x01;
		     break;		 
	     case 0b11101011: 
		     value = 0x02;
		     break;
	     case 0b11100111: 
		     value = 0x03;
		     break;
	     case 0b11011110: 
		     value = 0x04;
		     break;
	     case 0b11011101: 
		     value = 0x05;
		     break;
	     case 0b11011011: 
		     value = 0x06;
		     break;
	     case 0b11010111: 
		     value = 0x07;
		     break;
	     case 0b10111110: 
		     value = 0x08;
		     break;
	     case 0b10111101: 
		     value = 0x09;
		     break;
	     case 0b10111011: 
		     value = 0x0A;
		     break;
	     case 0b10110111: 
		     value = 0x0B;
		     break;
	     case 0b01111110: 
		     value = 0x0C;
		     break;
	     case 0b01111101: 
		     value = 0x0D;
		     break;
	     case 0b01111011: 
		     value = 0x0E;
		     break;
	     case 0b01110111: 
		     value = 0x0F;
		     break;	 
		 }
		   return value;
	}

void  row_data_r(void)
    {
	     row_data = PINB | 0xF0;
	     PORTB = row_data;
	     DDRB = ~row_data;
		   stage = 0x01;
     }
	 
void  col_data_r(void)
    {
	     col_data = PINB;
	     PORTB = 0x0F;
	     DDRB = 0xF0;
		    stage = 0x02;
		 PORTD = ~swin2hex(col_data);
     }

void  sw_off_chk(void)
    {
	   if (PINB != 0x0F)
	        stage = 0x02;
			else stage = 0xFF;
     }
	  
	 
#pragma interrupt_handler pcint0_isr:4
void pcint0_isr(void)
{
   PCMSK0 = 0x00;
   TCNT0 = 0xD9;
   TCCR0B = 0x04; //start timer
   PORTB = 0x0F;
   DDRB  = 0xF0;
   stage = 0x00;
}

//call this routine to initialize all peripherals
void init_devices(void)
{
 //stop errant interrupts until set up
 CLI(); //disable all interrupts
 port_init();
 timer0_init();

 MCUCR = 0x00;
 EICRA = 0x00; //extended ext ints
 EIMSK = 0x00;
 
 TIMSK0 = 0x01; //timer 0 interrupt sources
 TIMSK1 = 0x00; //timer 1 interrupt sources
 TIMSK2 = 0x00; //timer 2 interrupt sources
 
 PCMSK0 = 0x0F; //pin change mask PCNT0..3 Enabled
 PCMSK1 = 0x00; //pin change mask 1 
 PCMSK2 = 0x00; //pin change mask 2
 PCICR = 0x01; //pin change enable 
 PRR = 0x00; //power controller
 SEI(); //re-enable interrupts
 //all peripherals are now initialized
}

//
void main(void)
{
 init_devices();
   stage = 0xFF;
   while(1)
     {
	  SMCR =0x01;
	  asm("sleep\n");
	  if (stage ==0xFF)
	    {
	     PCMSK0 = 0x0F;
		 TCCR0B = 0x00; //stop timer
		}
	 }
}