/* timer.avr.c */ /* ai - Robot Artificial Intelligence. {{{ * * 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 "timer.h" #include "modules/utils/utils.h" #include "io.h" void timer_init (void) { /* Configuration of the timer/counter 0: * - top = 0xff, * - prescaler = 256, * -> Fov = F_io / (prescaler * (TOP + 1)) * -> Tov = 1 / Fov * Note: if you change the TCCR0 register value, please also update * TIMER_TC0_PRESCALER and TIMER_TC0_TOP. */ #ifdef TCCR0 # define TIFR_reg TIFR TCCR0 = regv (FOC0, WGM00, COM01, COM0, WGM01, CS02, CS01, CS00, 0, 0, 0, 0, 0, 1, 1, 0); #else # define TIFR_reg TIFR0 TCCR0A = regv (COM0A1, COM0A0, COM0B1, COM0B0, 3, 2, WGM01, WGM00, 0, 0, 0, 0, 0, 0, 0, 0); TCCR0B = regv (FOC0A, FOC0B, 5, 4, WGM02, CS02, CS01, CS00, 0, 0, 0, 0, 0, 1, 0, 0); #endif } uint8_t 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_reg & _BV (TOV0))) /* We have not reached overflow. */ count_before_ov = 0; /* Write 1 to clear overflow. */ TIFR_reg = _BV (TOV0); return count_before_ov; }