Abstract: A ID circuit produces a unique binary identification code (ID) for each integrated circuit in which it is implemented by setting states of each bit of the ID as a function of random variations in material forming the IC that occur at the time the IC is fabricated. The ID circuit includes an ID generating circuit for generating the ID, a non-volatile memory, and a control circuit for writing the ID generated by the ID generating circuit into the non-volatile memory in response to a first occurrence of a write cue event. Thereafter the control circuit responds to each occurrence of a read cue event by reading the ID out of the non-volatile memory and providing it as an IC output.

Abstract: A ID circuit produces a unique binary identification code (ID) for each integrated circuit in which it is implemented by setting states of each bit of the ID as a function of random variations in material forming the IC that occur at the time the IC is fabricated. The ID circuit includes an ID generating circuit for generating the ID, a non-volatile memory, and a control circuit for writing the ID generated by the ID generating circuit into the non-volatile memory in response to a first occurrence of a write cue event. Thereafter the control circuit responds to each occurrence of a read cue event by reading the ID out of the non-volatile memory and providing it as an IC output.