Practical methods for verifying removal of Trojan stable operating points

Several methods that can be used to verify effectiveness of startup circuits in eliminating known stable Trojan operating states will be discussed. It will be shown that some widely used approaches do not guarantee Trojan states have been removed. Some of the methods introduced appear to be more practical to work with than others. These methods can also be used to identify the presence of unknown stable Trojan states in many useful circuits.