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/* timer.c */
/*  {{{
 *
 * Copyright (C) 2004 Nicolas Schodet
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Contact :
 *        Web: http://perso.efrei.fr/~schodet/
 *      Email: <contact@ni.fr.eu.org>
 * }}} */
#include "timer.h"
#include <avr/io.h>
#include <n/avr/utils/utils.h>

/* +AutoDec */
/* -AutoDec */

/** Initialise the timer. */
inline void
timer_init (void)
{
    /* 1024 prescaler. */
    TCCR0 = regv (FOC0, WGM00, COM01, COM0, WGM01, CS02, CS01, CS00,
		     0,     0,     0,    0,     0,    1,    1,    0);
    /* Fov = F_io / (prescaler * (TOP + 1))
     * Tov = 1 / Fov = 4.44 ms */
}

/* Test if a overflow occured and reset the flag. */
inline int
timer_pending (void)
{
    if (TIFR & _BV (TOV0))
      {
	/* Write 1 to clear. */
	TIFR |= _BV (TOV0);
	return 1;
      }
    else
	return 0;
}