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Diffstat (limited to 'digital/io/src/main_timer.avr.c')
-rw-r--r--digital/io/src/main_timer.avr.c58
1 files changed, 58 insertions, 0 deletions
diff --git a/digital/io/src/main_timer.avr.c b/digital/io/src/main_timer.avr.c
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+++ b/digital/io/src/main_timer.avr.c
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+/* 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)
+{
+ /* Fov = F_io / (prescaler * (TOP + 1))
+ * TOP = 0xff
+ * prescaler = 256
+ * Tov = 1 / Fov = 4.444 ms */
+ /* Note: if you change this, update MT_TC0_*. */
+ TCCR0 = regv (FOC0, WGM00, COM01, COM0, WGM01, CS02, CS01, CS00,
+ 0, 0, 0, 0, 0, 1, 1, 0);
+}
+
+uint8_t
+main_timer_wait (void)
+{
+ /* We have reached overflow. */
+ 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;
+}