Only two decades ago most electronic circuits were designed with a slide-rule, and the designs were verified using breadboard techniques. Simulation tools were a research curiosity and in general were mistrusted by most designers and test engineers. In those days the programs were not user friendly, models were inadequate, and the algorithms were not very robust. The demand for simulation tools has been driven by the increasing complexity of integrated circuits and systems, and it has been aided by the rapid decrease in the cost of com puting that has occurred over the past several decades. Today a wide range of tools exist for analYSiS, deSign, and verification, and expert systems and synthesis tools are rapidly emerging. In this book only one aspect of the analysis and design process is examined. but it is a very important aspect that has received much attention over the years. It is the problem of accurate circuit and timing simulation.

Digital Timing Macromodeling for VLSI Design Verification first of all provides an extensive history of the development of simulation techniques. It presents detailed discussion of the various techniques implemented in circuit, timing, fast-timing, switch-level timing, switch-level, and gate-level simulation. It also discusses mixed-mode simulation and interconnection analysis methods. The review in Chapter 2 gives an understanding of the advantages and disadvantages of the many techniques applied in modern digital macromodels. The book also presents a wide variety of techniques for performing nonlinear macromodeling of digital MOS subcircuits which address a large number of shortcomings in existing digital MOS macromodels. Specifically, the techniques address the device model detail, transistor coupling capacitance, effective channel length modulation, series transistor reduction, effective transconductance, input terminal dependence, gate parasitic capacitance, the body effect, the impact of parasitic RC-interconnects, and the effect of transmission gates. The techniques address major sources of errors in existing macromodeling techniques, which must be addressed if macromodeling is to be accepted in commercial CAD tools by chip designers. The techniques presented in Chapters 4-6 can be implemented in other macromodels, and are demonstrated using the macromodel presented in Chapter 3. The new techniques are validated over an extremely wide range of operating conditions: much wider than has been presented for previous macromodels, thus demonstrating the wide range of applicability of these techniques.

This book provides the reader with an extensive background in the field of logic-timing simulation and delay modeling. It includes detailed information on the challenges of logic-timing simulation, applications, advantages and drawbacks. The capabilities of logic-timing are explored using the latest research results that are brought together from previously disseminated materials. An important part of the book is devoted to the description of the ?Degradation Delay Model?, developed by the authors, showing how the inclusion of dynamic effects in the modeling of delays greatly improves the application cases and accuracy of logic-timing simulation. These ideas are supported by simulation results extracted from a wide range of practical applications.Sample Chapter(s)

Abstract: "Accurate timing simulation of today's integrated circuits requires proper modeling of the RC interconnect among the transistors. However, most timing simulators obtain their efficiency over circuit simulation in terms of explicit integration algorithms that have difficulty handling the stiff RC circuit models which characterize interconnect-dominated paths. Circuit simulators such as SPICE or ASTAP can properly handle large RC interconnect models, but at a significant runtime penalty. For this reason there have been several N-port interconnect macromodels proposed to reduce the circuit simulation complexity. Unfortunately, as the number of ports increases, the runtime cost of the N-port macromodel can be greater than that for the flattened circuit. Due to the explicit integration techniques that are applied, stiff circuits represent an even more difficult problem for timing simulators, thereby negating their efficiency advantage over circuit simulators for analyzing large digital circuits at the transistor level. In this paper we describe an efficient, accurate, stable reduced-order N- port macromodel for timing simulation. This macromodel is shown to improve the timing simulation efficiency dramatically since it alleviates the stiff circuit problem. Moreover, through its compatibility with the simple timing simulation transistor models, it is shown that this macromodel does not suffer from the dramatic increase in complexity with an increase in the number of ports like circuit simulation. Therefore, this paper, 1) demonstrates the effectiveness of timing simulation for interconnect- dominated digital circuits, and 2) considers the effectiveness of using timing simulation and interconnect macromodels for simulating circuits with a large number of macromodel ports."

The International Workshop on Power and Timing Modeling, Optimization, and Simulation PATMOS 2002, was the 12th in a series of international workshops 1 previously held in several places in Europe. PATMOS has over the years evolved into a well-established and outstanding series of open European events on power and timing aspects of integrated circuit design. The increased interest, espe- ally in low-power design, has added further momentum to the interest in this workshop. Despite its growth, the workshop can still be considered as a very - cused conference, featuring high-level scienti?c presentations together with open discussions in a free and easy environment. This year, the workshop has been opened to both regular papers and poster presentations. The increasing number of worldwide high-quality submissions is a measure of the global interest of the international scienti?c community in the topics covered by PATMOS. The objective of this workshop is to provide a forum to discuss and inves- gate the emerging problems in the design methodologies and CAD-tools for the new generation of IC technologies. A major emphasis of the technical program is on speed and low-power aspects with particular regard to modeling, char- terization, design, and architectures. The technical program of PATMOS 2002 included nine sessions dedicated to most important and current topics on power and timing modeling, optimization, and simulation. The three invited talks try to give a global overview of the issues in low-power and/or high-performance circuit design.

This edition provides an important contemporary view of a wide range of analog/digital circuit blocks, the BSIM model, data converter architectures, and more. The authors develop design techniques for both long- and short-channel CMOS technologies and then compare the two.