diff --git a/myhdl/test_intbvbounds.py b/myhdl/test_intbvbounds.py
new file mode 100644
index 00000000..51269321
--- /dev/null
+++ b/myhdl/test_intbvbounds.py
@@ -0,0 +1,157 @@
+#  This file is part of the myhdl library, a Python package for using
+#  Python as a Hardware Description Language.
+#
+#  Copyright (C) 2003 Jan Decaluwe
+#
+#  The myhdl library is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU Lesser General Public License as
+#  published by the Free Software Foundation; either version 2.1 of the
+#  License, or (at your option) any later version.
+#
+#  This library is distributed in the hope that it will be useful, but
+#  WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+#  Lesser General Public License for more details.
+
+#  You should have received a copy of the GNU Lesser General Public
+#  License along with this library; if not, write to the Free Software
+#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+""" Run the intbv unit tests. """
+
+__author__ = "Jan Decaluwe <jan@jandecaluwe.com>"
+__revision__ = "$Revision$"
+__date__ = "$Date$"
+
+import unittest
+from unittest import TestCase
+import random
+from random import randrange
+random.seed(2) # random, but deterministic
+import sys
+maxint = sys.maxint
+import operator
+
+from intbv import intbv
+
+class TestIntbvBounds(TestCase):
+    
+    def testConstructor(self):
+        self.assertEqual(intbv(40, max=54), 40)
+        try:
+            intbv(40, max=27)
+        except ValueError:
+            pass
+        else:
+            self.fail()
+        self.assertEqual(intbv(25, min=16), 25)
+        try:
+            intbv(25, min=27)
+        except ValueError:
+            pass
+        else:
+            self.fail()
+
+
+    def testSliceAssign(self):
+        a = intbv(min=-24, max=34)
+        for i in (-24, -2, 13, 33):
+            a[:] = i
+            a[10:] = i
+        for i in (-25, -128, 34, 35, 229):
+            try:
+                a[:] = i
+                a[10:] = i
+            except ValueError:
+                pass
+            else:
+                self.fail()
+
+
+    def checkBounds(self, i, j, op):
+        a = intbv(i)
+        self.assertEqual(a, i) # just to be sure
+        try:
+            exec("a %s long(j)" % op)
+        except (ZeroDivisionError, ValueError):
+            return # prune
+        if not isinstance(a._val, (int, long)):
+            return # prune
+        if a > i:
+            b = intbv(i, min=i, max=a+1)
+            for m in (i+1, a):
+                b = intbv(i, min=i, max=m)
+                try:
+                    exec("b %s long(j)" % op)
+                except ValueError:
+                    pass
+                else:
+                    self.fail()
+        elif a < i :
+            b = intbv(i, min=a, max=i+1)
+            exec("b %s long(j)" % op) # should be ok
+            for m in (a+1, i):
+                b = intbv(i, min=m, max=i+1)
+                try:
+                    exec("b %s long(j)" % op)
+                except ValueError:
+                    pass
+                else:
+                    self.fail()
+        else: # a == i
+            b = intbv(i, min=i, max=i+1)
+            exec("b %s long(j)" % op) # should be ok
+            
+    def checkOp(self, op):
+        for i in (0, 1, -1, 2, -2, 16, -24, 129, -234, 1025, -15660):
+            for j in (0, 1, -1, 2, -2, 9, -15, 123, -312, 2340, -23144):
+                self.checkBounds(i, j, op)
+                
+    def testIAdd(self):
+        self.checkOp("+=")
+
+    def testISub(self):
+        self.checkOp("-=")
+        
+    def testIMul(self):
+        self.checkOp("*=") 
+        
+    def testIFloorDiv(self):
+        self.checkOp("//=")
+        
+    def testIMod(self):
+        self.checkOp("%=")
+
+    def testIPow(self):
+        self.checkOp("**=")
+
+    def testIAnd(self):
+        self.checkOp("&=")
+        
+    def testIOr(self):
+        self.checkOp("|=")
+        
+    def testIXor(self):
+        self.checkOp("^=")
+        
+    def testILShift(self):
+        self.checkOp("<<=")
+        
+    def testIRShift(self):
+        self.checkOp(">>=")
+                    
+            
+        
+        
+        
+        
+       
+
+
+        
+
+
+if __name__ == "__main__":
+    unittest.main()
+       
+