Micropipeline-Based Asynchronous Design Methodology for Robust System Design Using Nanoscale Crossbar

Rajat Subhra Chakraborty and Swarup Bhunia
Case Western Reserve University


Nanoscale molecular electronic devices amenable to bottom-up self-assembly process are promising candidates for future electronic systems. System design with these devices, however, will require developing new circuit and architectural techniques to exploit highly dense and regular structures such as nanoscale crossbar fabricated from them. It also requires addressing some inherent limitations of these devices, such as large process variations, high defect rates, lack of voltage gain (preventing logic cascading), and large overhead of interfacing logic. We propose an asynchronous design paradigm for nanoscale crossbar that combines them with CMOS-based event-driven bistable elements to implement micropipeline structures. An automated design platform for synthesizing these systems is also presented. The proposed asynchronous design approach addresses three main issues with nanoscale crossbar: 1) parameter variations, 2) logic cascading, and 3) large overhead of interfacing logic. Simulation results show considerable improvement in robustness under variations as well as in total area (up to 1.8X), delay (up to 2X) and power (up to 3.2X) compared to equivalent sequential implementation.