#ifndef main_timer_avr_h #define main_timer_avr_h /* main_timer.avr.h */ /* io - Input & Output with Artificial Intelligence (ai) support on AVR. {{{ * * Copyright (C) 2008 Dufour Jérémy * * APBTeam: * Web: http://apbteam.org/ * Email: team AT apbteam DOT org * * 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. * * }}} */ /** * @file Main timer module. * Main timer module is used for the main loop of the io board to ensure it is * executed only to the defined loop time (at the maximum). It uses the * timer/counter 0 of the AVR. */ /** * Initialize the main timer to 4.444 ms. */ static inline void main_timer_init (void) { /* Fov = F_io / (prescaler * (TOP + 1)) * TOP = 0xff * prescaler = 256 * Tov = 1 / Fov = 4.444 ms */ TCCR0 = regv (FOC0, WGM00, COM01, COM0, WGM01, CS02, CS01, CS00, 0, 0, 0, 0, 0, 1, 1, 0); } /** * Wait until the main timer overflows. */ static inline void main_timer_wait (void) { /* Loop until an overflow of the timer occurs */ while (!(TIFR & _BV (TOV0))) ; /* Write 1 to clear */ TIFR = _BV (TOV0); } #endif /* main_timer_avr_h */