Memory, Microprocessor, and ASIC

Wai-Kai Chen, Wai-Kai Chen

• Publisher: CRC Press
• Year: 2003
• ISBN:
  9781135499259
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

Timing, memory, power dissipation, testing, and testability are all crucial elements of VLSI circuit design. In this volume culled from the popular VLSI Handbook, experts from around the world provide in-depth discussions on these and related topics. Stacked gate, embedded, and flash memory all receive detailed treatment, including their power cons

1

System Timing

Ivan S.Kourtev
University of Pittsburgh

Eby G.Friedman
University of Rochester

1.1 Introduction

1.2 Synchronous VLSI Systems
General Overview • Advantages and Drawbacks of Synchronous Systems

1.3 Synchronous Timing and Clock
Distribution Networks
Background • Definitions and Notation • Clock Scheduling • Structure of the Clock Distribution Network

1.4 Timing Properties of Synchronous
Storage Elements
Common Storage Elements • Storage Elements • Latches • Flip-Flops • The Clock Signal • Analysis of a Single-Phase Local Data Path with Flip-Flops • Analysis of a Single-Phase Local Data Path with Latches

1.5 A Final Note

1.6 Glossary of Terms

1.1 Introduction

The concept of data or information processing arises in a variety of fields. Understanding the principles behind this concept is fundamental to computer design, communications, manufacturing process control, biomedical engineering, and an increasingly large number of other areas of technology and science. It is impossible to imagine modern life without computers for generating, analyzing, and retrieving large amounts of information, as well as communicating information to end users regardless of their location.

Technologies for designing and building microelectronics-based computational equipment have been steadily advancing ever since the first commercial discrete integrated circuits were introduced* in the late 1950s.¹ As predicted by Moore’s law in the 1960s,² integrated circuit (IC) density has been doubling approximately every 18 months, and this doubling in size has been accompanied by a similar exponential increase in circuit speed (or, more precisely, clock frequency). These trends of steadily increasing circuit size and clock frequency are illustrated in Fig. 1.1 (a) and (b), respectively. As a result of this amazing revolution in semiconductor technology, it is not unusual for modern integrated circuits to contain over ten million switching elements (i.e., transistors) packed into a chip area as large as 500 mm².^3-5 This truly exceptional technological capability is due to advances in both design methodologies and physical manufacturing technologies. Research and experience demonstrate that this trend of exponentially increasing integrated circuit computational power will continue into the foreseeable future.

Integrated circuit performance is typically characterized⁶ by the speed of operation, the available circuit functionality, and the power consumption, and there are multiple factors which directly affect these performance characteristics. While each of these factors is significant, on the technological side, increased circuit performance has been largely achieved by the following approaches:

FIGURE 1.1 Moore’s law: exponential increase in circuit integration and clock frequency. (From Rabaey, J.M., Digital Integrated Circuits: A Design Perspective, Prentice Hall, Inc., 1995.)

• Reduction in feature size (technology scaling); that is, the capability of manufacturing physically smaller and faster device structures
• Increase in chip area, permitting a larger number of circuits and therefore greater on-chip functionality
• Advances in packaging technology, permitting the increasing volume of data traffic between an integrated circuit and its environment as well as the efficient removal of heat created during circuit operation

The most complex integrated circuits are referred to as VLSI circuits, where the term “VLSI” stands for Very Large-Scale Integration. This term describes the complexity of modern integrated circuits consisting of hundreds of thousands to many millions of active transistor elements. Presently, the leading integrated circuit manufacturers have a technological capability for the mass production of VLSI circuits with feature sizes as small as 0.12 μm.⁷ These sub-1/2-micrometer technologies are identified with the te...