/* main_timer.avr.c */ /* io - Input & Output with Artificial Intelligence (ai) support on AVR. {{{ * * Copyright (C) 2009 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. * * }}} */ #include "common.h" #include "main_timer.h" #include "modules/utils/utils.h" #include "io.h" void main_timer_init (void) { /* Configuration of the timer/counter 0: * - top = 0xff, * - prescaler = 256, * -> Fov = F_io / (prescaler * (TOP + 1)) * -> Tov = 1 / Fov = 4.444 ms. * Note: if you change the TCCR0 register value, please also update * MT_TC0_PRESCALER and MT_TC0_TOP. */ TCCR0 = regv (FOC0, WGM00, COM01, COM0, WGM01, CS02, CS01, CS00, 0, 0, 0, 0, 0, 1, 1, 0); } uint8_t main_timer_wait (void) { /* Let's pretend we have reached overflow before calling this function. */ uint8_t count_before_ov = 1; /* Loop until an overflow of the timer occurs. */ while (!(TIFR & _BV (TOV0))) /* We have not reached overflow. */ count_before_ov = 0; /* Write 1 to clear overflow. */ TIFR = _BV (TOV0); return count_before_ov; }