diff -r 13ffc0066b76 -r 3c0e4e380689 src/python/m5/simulate.py
--- a/src/python/m5/simulate.py	Thu Jul 11 21:57:04 2013 -0500
+++ b/src/python/m5/simulate.py	Fri Jul 12 10:48:03 2013 +0100
@@ -57,8 +57,8 @@
 from util import fatal
 from util import attrdict
 
-# define a MaxTick parameter
-MaxTick = 2**63 - 1
+# define a MaxTick parameter, unsigned 64 bit
+MaxTick = 2**64 - 1
 
 _memory_modes = {
     "atomic" : objects.params.atomic,