/* Copyright (C) 2007 DJ Delorie

   Licensed under the terms of the GNU General Public license, either
   version 2 or (your choice) any later version.
*/

#include "r8c27.h"

#define A 0x04
#define B 0x40
#define C 0x01
#define D 0x10
#define E 0x08
#define F 0x80
#define G 0x20
#define H 0x02

static unsigned char font[] = {
  A|B|C|D|E|F,
  B|C,
  A|B|G|E|D,
  A|B|G|C|D,
  F|G|B|C,
  A|F|G|C|D,
  A|F|E|D|C|G,
  A|B|C,
  A|B|C|D|E|F|G,
  G|F|A|B|C|D,
  E|F|A|B|C|G,
  F|E|G|C|D,
  A|F|E|D,
  B|C|G|E|D,
  A|F|G|E|D,
  A|F|G|E
};

static volatile int tick;

static char digits[8];
static int didx = 0;

static __attribute__((interrupt))
timer_ra_isr ()
{
  unsigned char c;

  if (tick)
    tick--;

  pd1 = 0;
  c = font[digits[didx]];
  if (didx == 4)
    c |= H;
  prcr.prc2 = 1; /* disable pd0 protection */
  pd0 = c;
  pd1 = 1 << didx;
  didx = (didx+1) & 7;
}

main()
{
  unsigned int i = 0;
  unsigned int j = 0;
  unsigned int b = 0;

  /* TIMERS */
  tracr.b = 0x00;
  traioc.b = 0x00;
  tramr.b = 0x00; /* timer mode, f1 */
  trapre = 100; /* prescaler */
  tra = 200; /* cycle count */

  set_ivect (timer_ra_isr, ivec_timer_ra);
  traic = 5;

  tracr.tstart = 1;

  /* PORTS */
  p1drr = 0xff;
  p0 = 0xff;
  p1 = 0x00;

  prcr.prc2 = 1; /* disable pd0 protection */
  pd0 = 0x18;
  pd1 = 0x18;

  /* MAIN */
  b = 0x01;

  for (i=0; i<8; i++)
    digits[i] = 0;

  i = 0;
  j = 0;
  while (1)
    {
      while (tick)
	;
      tick = 1;

      for (i=7; i>=0; i--)
	if (digits[i] == 9)
	  digits[i] = 0;
	else
	  {
	    digits[i]++;
	    break;
	  }
    }
}