Evolution of Polymorphic Self-checking Circuits

Abstract

This paper presents elementary circuit components which exhibit self-checking properties; however, which do not utilize any additional signals to indicate the fault. The fault is indicated by generating specific values at some of standard outputs of a given circuit. In particular, various evolved adders containing conventional as well as polymorphic gates are proposed with less than duplication overhead which are able to detect a reasonable number of stuck-at-faults by oscillations at the carry-out output when the control signal of polymorphic gates oscillates.

REPOMO32 - New reconfigurable polymorphic integrated circuit for adaptive hardware

“…In particular, we plan to employ REPOMO32 in the area of circuit diagnostics and security. The "second" function provided by polymorphic gates can be activated in test mode of a circuit in order to detect faults [11] or reduce the number of test vectors [10], [16]. In the area of security, polymorphic gates can implement "invisible" functions which can be activated under special conditions.…”

“…This gate exhibits a very unconventional structure; in particular, it does not follow the wellaccepted rules for transistor-level design of CMOS gates. Then, researchers have begun to develop the methods for polymorphic circuits synthesis and integrate the polymorphic gates to various digital circuits to enhance their functionality [10], [11], [12], [13], [14], [15], [16]. Almost exclusively, the experiments were done using simulators.…”

Physical Demonstration of Polymorphic Self-Checking Circuits

“…In our recent work, we proposed a 1-bit adder which exhibits self-checking properties; however, which does not utilize any additional signals to indicate a fault [10,11]. Figure 4 shows that the sum calculation is quite standard.…”

“…A fault is indicated by oscillations at the C out output of the adder. This concept was introduced and simulated in our previous work [10,11]. This paper moves the approach from simulations to reality.…”

A Matching Outputs Approach to Evolutionary Design of Polymorphic Self-Checking Circuits

“…In order to reduce the overall cost and wiring, the new circuits in which the user function is completely merged with the test procedure are proposed. Sekanina utilized polymorphic gates to design self-checking circuits which indicate the faulty behavior by oscillations at one of their outputs, while no additional input/output signal wires are needed and the user function is merged with the test procedure [2]. By using the method in [2], Rucizka implemented the physical demonstration of self-checking adders based on NAND/NOR polymorphic gate to verify the feasibility of polymorphic method [3].…”