Date of Graduation


Document Type


Degree Name

Doctor of Philosophy in Engineering (PhD)

Degree Level



Electrical Engineering


Scott C. Smith

Committee Member

Waleed K. Al-Assadi

Second Committee Member

Jia Di

Third Committee Member

Alan Mantooth

Fourth Committee Member

Jingxian Wu


Asynchronous, MTNCL, NCL, NULL Convention Logic, SCL, Sleep Convention Logic


Delay-insensitive asynchronous circuits have been the target of a renewed research effort because of the advantages they offer over traditional synchronous circuits. Minimal timing analysis, inherent robustness against power-supply, temperature, and process variations, reduced energy consumption, less noise and EMI emission, and easy design reuse are some of the benefits of these circuits. NULL Convention Logic (NCL) is one of the mainstream asynchronous logic design paradigms that has been shown to be a promising method for designing delay-insensitive asynchronous circuits.

This dissertation investigates new areas in NCL design and test and is made of three sections. The first section discusses different CMOS implementations of NCL gates and proposes new circuit techniques to enhance their operation. The second section focuses on mapping multi-rail logic expressions to a standard NCL gate library, which is a form of technology mapping for a category of NCL design automation flows. Finally, the last section proposes design for testability techniques for a recently developed low-power variant of NCL called Sleep Convention Logic (SCL).