1 files changed, 39 insertions, 8 deletions
diff --git a/src/main/scala/Chisel/CoreUtil.scala b/src/main/scala/Chisel/CoreUtil.scala
index 41266cae..aaca404b 100644
--- a/src/main/scala/Chisel/CoreUtil.scala
+++ b/src/main/scala/Chisel/CoreUtil.scala
@@ -7,21 +7,52 @@ import internal.Builder.pushCommand
 import firrtl._
 
 object assert {
+  /** Checks for a condition to be valid in the circuit at all times. If the
+    * condition evaluates to false, the circuit simulation stops with an error.
+    *
+    * Does not fire when in reset (defined as the encapsulating Module's
+    * reset). If your definition of reset is not the encapsulating Module's
+    * reset, you will need to gate this externally.
+    *
+    * May be called outside of a Module (like defined in a function), so
+    * functions using assert make the standard Module assumptions (single clock
+    * and single reset).
+    *
+    * @param cond condition, assertion fires (simulation fails) when false
+    * @param message optional message to print when the assertion fires
+    */
   def apply(cond: Bool, message: String="") {
-    when(!cond) {
-      if (message.isEmpty()) {
-        printf(s"Assertion failed: (TODO: code / lineno)")
-      } else {
-        printf(s"Assertion failed: (TODO: code / lineno): $message")
+    when (!Builder.dynamicContext.currentModule.get.reset) {
+      when(!cond) {
+        if (message.isEmpty()) {
+          printf(s"Assertion failed: (TODO: code / lineno)")
+        } else {
+          printf(s"Assertion failed: (TODO: code / lineno): $message")
+        }
+        pushCommand(Stop(Node(Builder.dynamicContext.currentModule.get.clock), 1))
       }
-      pushCommand(Stop(Node(Builder.dynamicContext.currentModule.get.clock), 1))
     }
   }
 }
 
 object printf {
+  /** Prints a message in simulation.
+    *
+    * Does not fire when in reset (defined as the encapsulating Module's
+    * reset). If your definition of reset is not the encapsulating Module's
+    * reset, you will need to gate this externally.
+    *
+    * May be called outside of a Module (like defined in a function), so
+    * functions using printf make the standard Module assumptions (single clock
+    * and single reset).
+    *
+    * @param fmt printf format string
+    * @param data format string varargs containing data to print
+    */
   def apply(fmt: String, data: Bits*) {
-    pushCommand(Printf(Node(Builder.dynamicContext.currentModule.get.clock),
-        fmt, data.map(Node(_))))
+    when (!Builder.dynamicContext.currentModule.get.reset) {
+      pushCommand(Printf(Node(Builder.dynamicContext.currentModule.get.clock),
+          fmt, data.map((d: Bits) => d.ref)))
+    }
   }
 }