1 files changed, 26 insertions, 0 deletions
diff --git a/c/timer/timerctc.c b/c/timer/timerctc.c
new file mode 100644
index 0000000..7e65b52
--- /dev/null
+++ b/c/timer/timerctc.c
@@ -0,0 +1,26 @@
+#include <avr/io.h>
+
+enum{
+	Dcnt	= 62499	/* 1Hz */
+};
+
+int
+main()
+{
+	int led;
+
+	led = 1<<PB1;
+	DDRB |= led;
+	TCCR1B |= 1<<CS12;	/* f/256 prescaling */
+	TCCR1B |= 1<<WGM12;	/* ctc op mode */
+	OCR1A = Dcnt;		/* setup TOP */
+
+	for(;;){
+		/* check if we reached TOP */
+		if(TIFR1 & (1<<OCF1A)){
+			PORTB ^= led;
+			TIFR1 = 1<<OCF1A;	/* reset the flag */
+		}
+	}
+}
+