summaryrefslogtreecommitdiff
path: root/timer.h
diff options
context:
space:
mode:
authortmk <nobody@nowhere>2011-09-17 22:39:50 +0900
committertmk <nobody@nowhere>2011-09-17 23:53:18 +0900
commite67c988824f5ec0c965beb412f8ee5953dfd3c8c (patch)
tree190543f5bddfd31a326234aad91a0a995e55863a /timer.h
parentb703de7b298f8463bf4654fa3730ba1958a7fa9e (diff)
Added Bulegiga iWRAP support into HHKB.(Bluetooth)
Diffstat (limited to 'timer.h')
-rw-r--r--timer.h21
1 files changed, 20 insertions, 1 deletions
diff --git a/timer.h b/timer.h
index 402d4acc1e..f9e8181e6f 100644
--- a/timer.h
+++ b/timer.h
@@ -20,7 +20,26 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
#include <stdint.h>
-#define TIMER_DIFF(a, b) ((a) >= (b) ? (a) - (b) : UINT16_MAX - (b) + (a))
+#ifndef TIMER_PRESCALER
+# if F_CPU > 16000000
+# define TIMER_PRESCALER 256
+# elif F_CPU >= 4000000
+# define TIMER_PRESCALER 64
+# else
+# define TIMER_PRESCALER 8
+# endif
+#endif
+#define TIMER_RAW_FREQ (F_CPU/TIMER_PRESCALER)
+#define TIMER_RAW TCNT0
+#define TIMER_RAW_TOP (TIMER_RAW_FREQ/1000)
+
+#if (TIMER_RAW_TOP > 255)
+# error "Timer0 can't count 1ms at this clock freq. Use larger prescaler."
+#endif
+
+#define TIMER_DIFF(a, b, max) ((a) >= (b) ? (a) - (b) : (max) - (b) + (a))
+#define TIMER_DIFF_RAW(a, b) TIMER_DIFF(a, b, UINT8_MAX)
+#define TIMER_DIFF_MS(a, b) TIMER_DIFF(a, b, UINT16_MAX)
extern volatile uint16_t timer_count;