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authorNicolas Schodet2011-05-02 23:28:00 +0200
committerNicolas Schodet2011-05-03 01:36:05 +0200
commitc34c7f4b78ddf31d422454cb440ed31647d9b964 (patch)
tree1a80e4384226fc4e07a16a1ad21cb3c5c88a9b95 /digital/ai/src/utils/timer.avr.c
parent092057218111adb25119f0099c5ad951a5b10d69 (diff)
digital/{ai,io}: move timer and chrono to ai
Diffstat (limited to 'digital/ai/src/utils/timer.avr.c')
-rw-r--r--digital/ai/src/utils/timer.avr.c59
1 files changed, 59 insertions, 0 deletions
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;
+}
+