Two versions of a reconfigurable logic element are developed for use in constructing afield-programmable gate array NULL convention logic (NCL) field-programmable gate array (FPGA): one with extra embedded registration capability, which requires additional area, and one without. Both versions can be configured as any of the 27 fundamental NCL gates, including resettable and inverting variations, and both can utilize embedded registration for gates with three or fewer inputs; however, only the version with the additional embedded registration capability can utilize embedded registration with four-input gates. These two approaches are compared with each other and with an existing approach, showing that both versions developed herein yield a more area efficient NCL circuit implementation, compared to the previous work. The two FPGA logic elements are simulated at the transistor level using the 1.8-V, 180-nm TSMC CMOS process.


Electrical and Computer Engineering

Keywords and Phrases

NULL Convention Logic (NCL); Asynchronous Logic Design; Delay-Insensitive Circuits; Field-Programmable Gate Array (FPGA); Reconfigurable Logic

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version

Final Version

File Type





© 2007 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jan 2007