From 8c5f5ba1823ac57f78ef6bec72fca93c45d0d2fa Mon Sep 17 00:00:00 2001
From: Nebuleon Fumika
Date: Wed, 6 Feb 2013 00:43:21 -0500
Subject: Document the auto CPU behavior a bit.

---
 source/nds/entry.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

(limited to 'source/nds')

diff --git a/source/nds/entry.cpp b/source/nds/entry.cpp
index 08e95cb..5cca41e 100644
--- a/source/nds/entry.cpp
+++ b/source/nds/entry.cpp
@@ -642,6 +642,18 @@ static unsigned int sync_next = 0;
 
 static unsigned int skip_rate= 0;
 
+/*
+ * Automatic CPU frequency support is here.
+ * Whenever, after one downclock determination interval, each frame rendered
+ * during it has been rendered at least as early as CPU_DOWNCLOCK_EARLY_TIME,
+ * lower the CPU frequency in response.
+ * If at least one frame has been early, but not early enough, the CPU
+ * frequency stays stable.
+ * If at least one frame has been late, the CPU will have be switched back
+ * to 396 MHz.
+ * This improves battery life to a certain extent.
+ */
+
 #define CPU_DOWNCLOCK_EARLY_TIME 293 /* 1 = 42.667 us. 391 = 16.67 ms */
 #define CPU_DOWNCLOCK_DETERMINATION_INTERVAL 46874 /* 23437 = 1 s */
 
-- 
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