LiChEn: Automated Electrical Characterization of Asynchronous Standard Cell Libraries

Abstract

Semi-custom design flows are a key factor for the rapid growth of integrated circuits and systems. They lower design complexity through the use of pre-designed and pre-characterized functional components called standard cells, instead of assuming that designers have to draw, place and connect each transistor. In this way, modeling of complex systems is easier. As CMOS technologies evolve into deep sub micron nodes, asynchronous techniques gain relevance in the research community, due to their ability to cope with problems that are hard to solve with the synchronous paradigm. However, several specific components required in asynchronous designs are not available in commercial standard cell libraries, which constrains asynchronous design to use approaches close to full-custom ones. This limits modularity and increases design complexity. Thus, one of the possibilities for enabling further advance of the asynchronous paradigm is the availability of asynchronous standard cell libraries. Albeit industrial tools provide reasonable support to asynchronous standard cells physical design, the characterization of these cells using standard tools is usually quite laborious. This work proposes the Library Characterization Environment (LiChEn), an open source tool applicable to automatically characterize typical asynchronous standard cells. The tool managed to successfully characterize a standard cell library with over five hundred asynchronous components.