summaryrefslogtreecommitdiff
path: root/n/asserv/src/timer.c
diff options
context:
space:
mode:
authorschodet2004-09-29 21:07:25 +0000
committerschodet2004-09-29 21:07:25 +0000
commit55b33a20a69479219745172575c4504acd52730d (patch)
tree64f847e19e623c32ed37f7429252c4e71034e013 /n/asserv/src/timer.c
parentce1909a893f3a4c799eb2f876b78cfb0cf16cbf6 (diff)
Initial revision
Diffstat (limited to 'n/asserv/src/timer.c')
-rw-r--r--n/asserv/src/timer.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/n/asserv/src/timer.c b/n/asserv/src/timer.c
new file mode 100644
index 0000000..b5d0b4d
--- /dev/null
+++ b/n/asserv/src/timer.c
@@ -0,0 +1,55 @@
+/* timer.c */
+/* {{{
+ *
+ * Copyright (C) 2004 Nicolas Schodet
+ *
+ * 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.
+ *
+ * Contact :
+ * Web: http://perso.efrei.fr/~schodet/
+ * Email: <contact@ni.fr.eu.org>
+ * }}} */
+#include "timer.h"
+#include <avr/io.h>
+#include <n/avr/utils/utils.h>
+
+/* +AutoDec */
+/* -AutoDec */
+
+/** Initialise the timer. */
+inline void
+timer_init (void)
+{
+ /* 1024 prescaler. */
+ TCCR0 = regv (FOC0, WGM00, COM01, COM0, WGM01, CS02, CS01, CS00,
+ 0, 0, 0, 0, 0, 1, 1, 0);
+ /* Fov = F_io / (prescaler * (TOP + 1))
+ * Tov = 1 / Fov = 4.44 ms */
+}
+
+/* Test if a overflow occured and reset the flag. */
+inline int
+timer_pending (void)
+{
+ if (TIFR & _BV (TOV0))
+ {
+ /* Write 1 to clear. */
+ TIFR |= _BV (TOV0);
+ return 1;
+ }
+ else
+ return 0;
+}
+