From 4420652549c1e8d4ec75507c8867872298c46a13 Mon Sep 17 00:00:00 2001
From: Jim McGee <madscifi@jetblackcat.com>
Date: Fri, 6 May 2011 22:30:33 -0700
Subject: [PATCH] Add standalone memory barrier function to project.

---
 memory_barrier.h | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 memory_barrier.h

diff --git a/memory_barrier.h b/memory_barrier.h
new file mode 100644
index 0000000..662f2de
--- /dev/null
+++ b/memory_barrier.h
@@ -0,0 +1,18 @@
+#ifndef _MEMORY_BARRIER_H_
+#define _MEMORY_BARRIER_H_
+
+#include <util/atomic.h>
+#include <avr/version.h>
+
+// Provide a memory barrier to the compiler. This informs
+// the compiler that is should write any cached values that
+// are destined for a global variable and discard any other
+// cached values from global variables.
+//
+// Note that this behavior does apply to all global variables,
+// not just volatile ones. However, cached local variables
+// are not affected as they are not externally visible.
+
+#define MEMORY_BARRIER() __asm volatile( "" ::: "memory" )
+
+#endif
\ No newline at end of file