diff --git a/configs/common/Options.py b/configs/common/Options.py
index e69f3a527..d5ea85090 100644
--- a/configs/common/Options.py
+++ b/configs/common/Options.py
@@ -27,9 +27,9 @@
 # Authors: Lisa Hsu
 
 # system options
-parser.add_option("-d", "--detailed", action="store_true")
-parser.add_option("-t", "--timing", action="store_true")
-parser.add_option("--inorder", action="store_true")
+parser.add_option("-c", "--cpu-type", type="choice", default="atomic",
+                  choices = ["atomic", "timing", "detailed", "inorder"],
+                  help = "type of cpu to run with")
 parser.add_option("-n", "--num-cpus", type="int", default=1)
 parser.add_option("--caches", action="store_true")
 parser.add_option("--l2cache", action="store_true")
diff --git a/configs/common/Simulation.py b/configs/common/Simulation.py
index 7abf478da..1897fa8cb 100644
--- a/configs/common/Simulation.py
+++ b/configs/common/Simulation.py
@@ -40,14 +40,14 @@ addToPath('../common')
 def setCPUClass(options):
 
     atomic = False
-    if options.timing:
+    if options.cpu_type == "timing":
         class TmpClass(TimingSimpleCPU): pass
-    elif options.detailed:
+    elif options.cpu_type == "detailed":
         if not options.caches:
             print "O3 CPU must be used with caches"
             sys.exit(1)
         class TmpClass(DerivO3CPU): pass
-    elif options.inorder:
+    elif options.cpu_type == "inorder":
         if not options.caches:
             print "InOrder CPU must be used with caches"
             sys.exit(1)
diff --git a/configs/example/se.py b/configs/example/se.py
index a34a03b29..56737d6d5 100644
--- a/configs/example/se.py
+++ b/configs/example/se.py
@@ -122,7 +122,7 @@ if options.errout != "":
 workloads = options.cmd
 numThreads = 1
 
-if options.detailed or options.inorder:
+if options.cpu_type == "detailed" or options.cpu_type == "inorder":
     #check for SMT workload
     workloads = options.cmd.split(';')
     if len(workloads) > 1:
@@ -154,10 +154,10 @@ if options.detailed or options.inorder:
     numThreads = len(workloads)
     
 if options.ruby:
-    if options.detailed:
+    if options.cpu_type == "detailed":
         print >> sys.stderr, "Ruby only works with TimingSimpleCPU!!"
         sys.exit(1)
-    elif not options.timing:
+    elif not options.cpu_type == "timing":
         print >> sys.stderr, "****WARN:  using Timing CPU since it's needed by Ruby"
 
     class CPUClass(TimingSimpleCPU): pass