Enhanced Duplication Method with TMR-Like Masking Abilities

This paper proposes a method improving the fault-coverage capabilities of Field Programmable Gate Array (FPGA) designs. Faults are mostly single event upsets (SEUs) in the configuration memory of SRAM-based FPGAs and they can change the functionality of an implemented design. These changes may lead to crucial mistakes and cause damage to people and environment. The proposed method utilizes Concurrent Error Detection (CED) techniques and the basic architectures of actual modern FPGAs -- the Look-Up Table (LUT) with two outputs. The Parity Waterfall method (based on a cascade -- waterfall -- of several waves of inner parity generating the final parity of outputs of the whole circuit) presented in our previous paper has been encapsulated into a Duplication scheme in this paper. This encapsulation allows us to create a system containing two independent copies of all parts able to detect and localize any single fault (like common Triple Modular Redundancy (TMR) method). Experiments are performed on the standard set of IWLS2005 benchmarks in our simulator. The results demonstrate differences between our proposed method in comparison with TMR -- the proposed method has a lower relative overhead and requires a lower number of inputs and outputs.