Timing Performance Of Nanometer Digital Circuits Under Process Variations

This book discusses the digital design of integrated circuits under process variations, with a focus on design-time solutions. The authors describe a step-by-step methodology, going from logic gates to logic paths to the circuit level. Topics are presented in comprehensively, without overwhelming use of analytical formulations. Emphasis is placed on providing digital designers with understanding of the sources of process variations, their impact on circuit performance and tools for improving their designs to comply with product specifications. Various circuit-level “design hints” are highlighted, so that readers can use then to improve their designs. A special treatment is devoted to unique design issues and the impact of process variations on the performance of FinFET based circuits. This book enables readers to make optimal decisions at design time, toward more efficient circuits, with better yield and higher reliability.

Welcome to the proceedings of PATMOS 2008, the 18th in a series of int- national workshops. PATMOS 2008 was organized by INESC-ID / IST - TU Lisbon, Portugal, with sponsorship by Cadence, IBM, Chipidea, and Tecmic, and technical co-sponsorship by the IEEE. Over the years, PATMOS has evolved into an important European event, where researchers from both industry and academia discuss and investigate the emerging challenges in future and contemporary applications, design meth- ologies, and tools required for the development of the upcoming generations of integrated circuits and systems. The technical program of PATMOS 2008 c- tained state-of-the-art technical contributions, three invited talks, and a special session on recon?gurable architectures. The technical program focused on t- ing, performance and power consumption, as well as architectural aspects with particular emphasis on modeling, design, characterization, analysis and op- mization in the nanometer era. The Technical Program Committee, with the assistance of additional expert reviewers, selected the 41 papers presented at PATMOS. The papers were - ganized into 7 oral sessions (with a total of 31 papers) and 2 poster sessions (with a total of 10 papers). As is customary for the PATMOS workshops, full papers were required for review, and a minimum of three reviews were received per manuscript.

This book provides a unified treatment of Flip-Flop design and selection in nanometer CMOS VLSI systems. The design aspects related to the energy-delay tradeoff in Flip-Flops are discussed, including their energy-optimal selection according to the targeted application, and the detailed circuit design in nanometer CMOS VLSI systems. Design strategies are derived in a coherent framework that includes explicitly nanometer effects, including leakage, layout parasitics and process/voltage/temperature variations, as main advances over the existing body of work in the field. The related design tradeoffs are explored in a wide range of applications and the related energy-performance targets. A wide range of existing and recently proposed Flip-Flop topologies are discussed. Theoretical foundations are provided to set the stage for the derivation of design guidelines, and emphasis is given on practical aspects and consequences of the presented results. Analytical models and derivations are introduced when needed to gain an insight into the inter-dependence of design parameters under practical constraints. This book serves as a valuable reference for practicing engineers working in the VLSI design area, and as text book for senior undergraduate, graduate and postgraduate students (already familiar with digital circuits and timing).

Since process variation and chip performance uncertainties have become more pronounced as technologies scale down into the nanometer regime, accurate and efficient modeling or characterization of variations from the device to the architecture level have become imperative for the successful design of VLSI chips. This book provides readers with tools for variation-aware design methodologies and computer-aided design (CAD) of VLSI systems, in the presence of process variations at the nanometer scale. It presents the latest developments for modeling and analysis, with a focus on statistical interconnect modeling, statistical parasitic extractions, statistical full-chip leakage and dynamic power analysis considering spatial correlations, statistical analysis and modeling for large global interconnects and analog/mixed-signal circuits. Provides readers with timely, systematic and comprehensive treatments of statistical modeling and analysis of VLSI systems with a focus on interconnects, on-chip power grids and clock networks, and analog/mixed-signal circuits; Helps chip designers understand the potential and limitations of their design tools, improving their design productivity; Presents analysis of each algorithm with practical applications in the context of real circuit design; Includes numerical examples for the quantitative analysis and evaluation of algorithms presented. Provides readers with timely, systematic and comprehensive treatments of statistical modeling and analysis of VLSI systems with a focus on interconnects, on-chip power grids and clock networks, and analog/mixed-signal circuits; Helps chip designers understand the potential and limitations of their design tools, improving their design productivity; Presents analysis of each algorithm with practical applications in the context of real circuit design; Includes numerical examples for the quantitative analysis and evaluation of algorithms presented.

The book provides a detailed analysis of issues related to sub-threshold interconnect performance from the perspective of analytical approach and design techniques. Particular emphasis is laid on the performance analysis of coupling noise and variability issues in sub-threshold domain to develop efficient compact models. The proposed analytical approach gives physical insight of the parameters affecting the transient behavior of coupled interconnects. Remedial design techniques are also suggested to mitigate the effect of coupling noise. The effects of wire width, spacing between the wires, wire length are thoroughly investigated. In addition, the effect of parameters like driver strength on peak coupling noise has also been analyzed. Process, voltage and temperature variations are prominent factors affecting sub-threshold design and have also been investigated. The process variability analysis has been carried out using parametric analysis, process corner analysis and Monte Carlo technique. The book also provides a qualitative summary of the work reported in the literature by various researchers in the design of digital sub-threshold circuits. This book should be of interest for researchers and graduate students with deeper insights into sub-threshold interconnect models in particular. In this sense, this book will best fit as a text book and/or a reference book for students who are initiated in the area of research and advanced courses in nanotechnology, interconnect design and modeling.

This monograph is motivated by the challenges faced in designing reliable VLSI systems in modern VLSI processes. The reliable operation of integrated circuits (ICs) has become increasingly dif?cult to achieve in the deep submicron (DSM) era. With continuouslydecreasing device feature sizes, combinedwith lower supply voltages and higher operating frequencies, the noise immunity of VLSI circuits is decreasing alarmingly. Thus, VLSI circuits are becoming more vulnerable to noise effects such as crosstalk, power supply variations, and radiation-inducedsoft errors. Among these noise sources, soft errors(or error caused by radiation particle strikes) have become an increasingly troublesome issue for memory arrays as well as c- binational logic circuits. Also, in the DSM era, process variations are increasing at a signi?cant rate, making it more dif?cult to design reliable VLSI circuits. Hence, it is important to ef?ciently design robust VLSI circuits that are resilient to radiation particle strikes and process variations. The work presented in this research mo- graph presents several analysis and design techniques with the goal of realizing VLSI circuits, which are radiation and process variation tolerant.

Uncertainty in key parameters within a chip and between different chips in the deep sub micron area plays a more and more important role. As a result, manufacturing process spreads need to be considered during the design process. Quantitative methodology is needed to ensure faultless functionality, despite existing process variations within given bounds, during product development. This book presents the technological, physical, and mathematical fundamentals for a design paradigm shift, from a deterministic process to a probability-orientated design process for microelectronic circuits. Readers will learn to evaluate the different sources of variations in the design flow in order to establish different design variants, while applying appropriate methods and tools to evaluate and optimize their design.

This book covers the state-of-the-art research in design of modern electronic systems used in safety-critical applications such as medical devices, aircraft flight control, and automotive systems. The authors discuss lifetime reliability of digital systems, as well as an overview of the latest research in the field of reliability-aware design of integrated circuits. They address modeling approaches and techniques for evaluation and improvement of lifetime reliability for nano-scale CMOS digital circuits, as well as design algorithms that are the cornerstone of Computer Aided Design (CAD) of reliable VLSI circuits. In addition to developing lifetime reliability analysis and techniques for clocked storage elements (such as flip-flops), the authors also describe analysis and improvement strategies targeting commercial digital circuits.