Cellular Array-based Delay-insensitive Asynchronous Circuits Design and Test for Nanocomputing Systems

Abstract

This paper presents the design, layout, and testability analysis of delay-insensitive circuits on cellular arrays for nanocomputing system design. In delay-insensitive circuits the delay on a signal path does not affect the correctness of circuit behavior. The combination of delay-insensitive circuit style and cellular arrays is a useful step to implement nanocomputing systems. In the approach proposed in this paper the circuit expressions corresponding to a design are first converted into Reed---Muller forms and then implemented using delay-insensitive Reed---Muller cells. The design and layout of the Reed---Muller cell using primitives has been described in detail. The effects of stuck-at faults in both delay-insensitive primitives and gates have been analyzed. Since circuits implemented in Reed---Muller forms constructed by the Reed---Muller cells can be easily tested offline, the proposed approach for delay-insensitive circuit design improves a circuit's testability. Potential physical implementation of cellular arrays and its area overhead are also discussed.