Reviving Erroneous Stability-based Clock-Gating using Partial Max-SAT

Abstract—The conflicting yet increasing demand for high performance and low power in multi-functional chips has pushed techniques for power reduction to the forefront of VLSI design. Although recent developments have automated most of the low power implementations, designers often manually modify the circuit in order to achieve further power savings. This human intervention is often paved with many errors that are bound to typical logic functional failures. Debugging these errors can be a resource intensive process that requires considerable manual effort. This discourages engineers and achieving power savings at the micro level of the design sometimes remains unrealized. This paper proposes a novel debugging methodology to rectify erroneous clock-gating implementations. With the use of Partial Max-SAT, the method localizes and rectifies the design error introduced in the circuit during a clock-gating implementation. The net effect of the proposed methodology leads to shorter debug time ensuring additional power savings. Extensive experiments on benchmark circuits confirm the effectiveness of the approach

Exploiting Satisfiability Solvers for Efficient Logic Synthesis

Logic synthesis is an important part of electronic design automation (EDA) flows, which enable the implementation of digital systems. As the design size and complexity increase, the data structures and algorithms for logic synthesis must adapt and improve in order to keep pace and to maintain acceptable runtime and high-quality results. Large circuits were often represented using binary decision diagrams (BDDs) that were rapidly adopted by logic synthesis tools beginning in the 1980s. Nowadays, BDD-based algorithms are still enhanced, but the possibilities for improvement are somewhat saturated after some 35 years of research. Alternatively, the first EDA applications that exploit Boolean satisfiability (SAT) were developed in the 1990s. Despite the worst-case exponential runtime of SAT solvers, rapid progress in their performance enabled the creation of efficient SAT-based algorithms. Yet, logic synthesis started using SAT solvers more diffusely only in the last decade. Therefore, thorough research is still required both for exploiting SAT solvers and for encoding logic synthesis problems into SAT. Our main goal in this thesis is to facilitate and promote the further integration of SAT solvers into EDA by proposing and evaluating novel SAT-based algorithms that can be used as building blocks in logic synthesis tools. First, we propose a rapid algorithm for LEXSAT, which generates satisfying assignments in lexicographic order. We show that LEXSAT can bring canonicity, which guarantees the generation of unique results, when using SAT solvers in EDA applications. Next, we present a new SAT-based algorithm that progressively generates irredundant sums of products (SOPs), which still play a crucial role in many logic synthesis tools. Using LEXSAT, for the first time, we can generate canonical SAT-based SOPs that, much like BDD-based SOPs, are unique for a given function and variable order but could relax canonicity in order to improve speed and scalability. Unlike BDDs, due to its progressive nature, our algorithm can generate partial SOPs for applications that can work with incomplete circuit functionality. It is noteworthy that both LEXSAT and the SAT-based SOPs are applicable beyond logic synthesis and EDA. Finally, we focus on resubstitution, which reimplements a given Boolean function as a new function that depends on a set of existing functions called divisors. We propose the carving interpolation algorithm that, unlike the traditional Craig interpolation, forces the use of a specific divisor as an input of the new function. This is particularly useful for global circuit restructuring and for some synthesis-based engineering change order (ECO) algorithms. Furthermore, we compare two existing SAT-based methodologies for resubstitution, which are used for post-mapping logic optimisation. The first methodology combines SAT-based functional dependency checking and Craig interpolation that are also used for our carving interpolation; the second methodology is based on cube enumeration and is similar to the SAT-based SOP generation. The initial implementations of our novel SAT-based algorithms offer either better performance or new features, or both, compared to their state-of-the-art versions. As the results indicate, a further thorough development of SAT-based algorithms for logic synthesis, like the one performed for BDDs in the past, can help overcome existing limitations and keep up with growing designs and design complexity

Recent advances in petri nets and concurrency

CEUR Workshop Proceeding

Celebrating Economies of Change: Brave Visions for Inclusive Futures

This issue has been inspired by a path-breaking conference held by the Canadian Society for Ecologi-cal Economics (CANSEE), which took place this past May 2019 in Waterloo, Ontario. Entitled Engaging Economies of Change, the conference aimed to ex-pand existing research networks in the economy-environment nexus by building connections beyond the academy in order to meaningfully engage with the practicalities of building and implementing change. This issue captures the rich content shared during the event, as well as descriptions of the pro-cesses and efforts made to create a welcoming and respectful space where academics and community activists could build alliances and discuss common challenges. The conference organizers – all graduate students and activists themselves -- called this ‘building a brave space’.This research was supported by the Social Sciences and Humanities Research Council of Canad

The Philosophy of The X-Files

In The Philosophy of The X-Files, Dean A. Kowalski has gathered a remarkable cast of contributors to shed light on the philosophical mysteries of the television show The X-Files. With sections devoted to the show’s credos, such as “The Truth Is Out There,” individual characters, and specific episodes, The Philosophy of The X-Files illuminates the philosophical assumptions and presuppositions of the show as well as presents discussions through the show to help the reader better understand philosophy and philosophical inquiry. Dean A. Kowalski, assistant professor of philosophy at the University of Wisconsin–Waukesha, is the author of Classic Questions and Contemporary Film: An Introduction to Philosophy and The Philosophy of Steven Spielberg.https://uknowledge.uky.edu/upk_american_popular_culture/1006/thumbnail.jp

Sustainability in design: now! Challenges and opportunities for design research, education and practice in the XXI century

Copyright @ 2010 Greenleaf PublicationsLeNS project funded by the Asia Link Programme, EuropeAid, European Commission

Bowdoin Orient v.115, no.1-27 (1985-1986)

https://digitalcommons.bowdoin.edu/bowdoinorient-1980s/1006/thumbnail.jp

Safety and Reliability - Safe Societies in a Changing World

The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk managemen

The life and work of the Revd. T.H.E.C. Espin perpetual curate of tow law with special reference to his astronomical research

Not availabl

The U.S. Army in the Iraq War – Volume 2: Surge and Withdrawal, 2007-2011

The Iraq War has been the costliest U.S. conflict since the Vietnam War. To date, few official studies have been conducted to review what happened, why it happened, and what lessons should be drawn. The U.S. Army in the Iraq War is the Army\u27s initial operational level analysis of this conflict, written in narrative format, with assessments and lessons embedded throughout the work. This study reviews the conflict from a Landpower perspective and includes the contributions of coalition allies, the U.S. Marine Corps, and special operations forces. Presented principally from the point of view of the commanders in Baghdad, the narrative examines the interaction of the operational and strategic levels, as well as the creation of theater level strategy and its implementation at the tactical level. Volume 1 begins in the truce tent at Safwan Airfield in southern Iraq at the end of Operation DESERT STORM and briefly examines actions by U.S. and Iraqi forces during the interwar years. The narrative continues by examining the road to war, the initially successful invasion, and the rise of Iraqi insurgent groups before exploring the country\u27s slide toward civil war. This volume concludes with a review of the decision by the George W. Bush administration to “surge” additional forces to Iraq, and reviews the conduct of the “surge” and its aftermath. This study was constructed over a span of 4 years and relied on nearly 30,000 pages of handpicked declassified documents, hundreds of hours of original interviews, and thousands of hours of previously unavailable interviews. Original interviews conducted by the team included President George W. Bush, Secretary of State Condoleezza Rice, Secretaries of Defense Leon Panetta and Robert Gates, Chairmen of the Joint Chiefs of Staff, and every theater commander for the war, among many others. With its release, this publication, The U.S. Army in the Iraq War, represents the U.S. Government\u27s longest and most detailed study of the Iraq conflict thus far.https://digitalcommons.usmalibrary.org/books/1019/thumbnail.jp