Assessment of nano-scale Muller C-elements under variability based on a new fault model

Muller C-elements are considered as a main component of in asynchronous circuits. The traditional implementations of C-elements require an accurate transistor sizing as it is based on some specific current driving assumptions. Due to process variability at nano-scale technology node, such constraints cannot be guaranteed which may lead to malfunction of C-elements. In this paper, we carry out a thorough vulnerability analysis of Muller C-element under process variations at nano-scale technology nodes introducing a new fault model. We model the process variation impacts as a new fault model called driving fault. Considering this fault model, we perform MC simulations to find the driving fault tolerance of different C-element implantations. Experimental results show that two C-element implementations are completely tolerant against driving faults. It is notable to mention that tradeoffs between the overheads and driving fault tolerance of C-element implementations demonstrate that it is worthy to use driving fault tolerant C-element implementations in nano-scale technology nodes with extreme process variations.