From c34c7f4b78ddf31d422454cb440ed31647d9b964 Mon Sep 17 00:00:00 2001 From: Nicolas Schodet Date: Mon, 2 May 2011 23:28:00 +0200 Subject: digital/{ai,io}: move timer and chrono to ai --- digital/ai/src/utils/timer.avr.c | 59 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 digital/ai/src/utils/timer.avr.c (limited to 'digital/ai/src/utils/timer.avr.c') diff --git a/digital/ai/src/utils/timer.avr.c b/digital/ai/src/utils/timer.avr.c new file mode 100644 index 00000000..b8756d88 --- /dev/null +++ b/digital/ai/src/utils/timer.avr.c @@ -0,0 +1,59 @@ +/* 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. */ + TCCR0 = regv (FOC0, WGM00, COM01, COM0, WGM01, CS02, CS01, CS00, + 0, 0, 0, 0, 0, 1, 1, 0); +} + +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 & _BV (TOV0))) + /* We have not reached overflow. */ + count_before_ov = 0; + /* Write 1 to clear overflow. */ + TIFR = _BV (TOV0); + return count_before_ov; +} + -- cgit v1.2.3