From edf5f145013aa28ffbc7f19f874cd489a92f8449 Mon Sep 17 00:00:00 2001
From: rodri <rgl@antares-labs.eu>
Date: Sat, 5 Jun 2021 11:10:23 +0000
Subject: public release.

---
 c/timer/timer.c    | 23 +++++++++++++++++++++++
 c/timer/timerctc.c | 26 ++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)
 create mode 100644 c/timer/timer.c
 create mode 100644 c/timer/timerctc.c

(limited to 'c/timer')

diff --git a/c/timer/timer.c b/c/timer/timer.c
new file mode 100644
index 0000000..f1231b1
--- /dev/null
+++ b/c/timer/timer.c
@@ -0,0 +1,23 @@
+#include <avr/io.h>
+
+enum{
+	Dcnt = 62499
+};
+
+int
+main()
+{
+	int led;
+
+	led = 1<<PB1;
+	DDRB |= led;
+	TCCR1B |= 1<<CS12;
+
+	for(;;){
+		if(TCNT1 >= Dcnt){
+			PORTB ^= led;
+			TCNT1 = 0;
+		}
+	}
+}
+
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 */
+		}
+	}
+}
+
-- 
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