From: Michel Pollet <buserror@gmail.com>
Date: Wed, 16 Feb 2011 00:03:28 +0000 (+0000)
Subject: timers: don't reconfigure for minor changes
X-Git-Url: http://git.rot13.org/?a=commitdiff_plain;h=b778a45f49549badc2980ac79ca18a4ae7b5c5b5;p=simavr

timers: don't reconfigure for minor changes

Prevents the timer to be reset when changing non important
bits, like the edge detector etc

Signed-off-by: Michel Pollet <buserror@gmail.com>
---

diff --git a/simavr/sim/avr_timer.c b/simavr/sim/avr_timer.c
index 3912e59..a218a67 100644
--- a/simavr/sim/avr_timer.c
+++ b/simavr/sim/avr_timer.c
@@ -295,8 +295,21 @@ static void avr_timer_write_ocr(struct avr_t * avr, avr_io_addr_t addr, uint8_t
 static void avr_timer_write(struct avr_t * avr, avr_io_addr_t addr, uint8_t v, void * param)
 {
 	avr_timer_t * p = (avr_timer_t *)param;
+
+	uint8_t as2 = avr_regbit_get(avr, p->as2);
+	uint8_t cs = avr_regbit_get_array(avr, p->cs, ARRAY_SIZE(p->cs));
+	uint8_t mode = avr_regbit_get_array(avr, p->wgm, ARRAY_SIZE(p->wgm));
+
 	avr_core_watch_write(avr, addr, v);
-	avr_timer_reconfigure(p);
+
+	// only reconfigure the timer if "relevant" bits have changed
+	// this prevent the timer reset when changing the edge detector
+	// or other minor bits
+	if (avr_regbit_get_array(avr, p->cs, ARRAY_SIZE(p->cs)) != cs ||
+			avr_regbit_get_array(avr, p->wgm, ARRAY_SIZE(p->wgm)) != mode ||
+					avr_regbit_get(avr, p->as2) != as2) {
+		avr_timer_reconfigure(p);
+	}
 }
 
 /*