META-MODELING META-MODELING Performance and Information Modeling Edited by Jean-Michel Berge CNET. France Oz Levia Cadence Design Systems. U.S.A. and Jacques Rouillard ESIM. France KLUWER ACADEMIC PUBLISHERS DORDRECHT I BOSTON I LONDON A C.I.P. Catalogue record for this book is available from the Library of Congress ISBN-13: 978-1-4612-8580-9 e-ISBN-13: 978-1-4613-1347-2 DOl: 10.1007/978-1-4613-1347-2 Published by Kluwer Academic Publishers, P.O. Box 17, 3300 AA Dordrecht, The Netherlands. Kluwer Academic Publishers incorporates the publishing programmes of D. Reidel, Martinus Nijhoff, Dr W. Junk and MTP Press. Sold and distributed in the U.S.A. and Canada by Kluwer Academic Publishers, 101 Philip Drive, Norwell, MA 02061, U.S.A. In all other countries, sold and distributed by Kluwer Academic Publishers Group, P.O. Box 322, 3300 AH Dordrecht, The Netherlands. Printed on acid-free paper All Rights Reserved @ 1996 Kluwer Academic Publishers Softcover reprint of the hardcover 15t edition 1996 No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage and retrieval system, without written permission from the copyright owner. SERIES PRESENTATION Current Issues in Electronic Modeling is a series of volumes publishing high quality, peer-reviewed papers dealing with modeling issues in the electronic domain. The objective is to establish a unique communication channel between academia and industry which will serve the growing needs in the field of modeling. PUBLISHED VOLUMES: • Volume 1: Model Generation in Electronic Modeling Contents: 1. A Flexible Generator of Component Models. 2. What Makes an ASIC Library Sign-Off? 3. A Case History in Building Vital-Compliant Models. 4. Modeling Multiple Driver Net Delay in Simulation. 5. DELPHI: the Development ofL ibrairies of Physical Models of Electronic Components for Integrated DeSign Environment. 6. VHDL Floating Point OperatiOns. 7. Symbolic Model Checking with Past and Future Temporal Modalities: Fundamentals and Algorithms. 8. KRYPTON: Portable, Non Reversible Encryptionfor VHDL. Index. 168 pp. ISBN 0-7923-9568-9 • Volume 2: Modeling in Analog Design Contents: 1. VHDL-A Design Objectives and Rationale. 2. Modeling in VHDL-A: Devices, Networks and Systems. 3. Analog Modeling using MHDL. 4. Modeling and Simulation of Electrical and Thermal Interaction. 5. Modeling of Power MOSFET. Index. 176 pp. ISBN 0-7923-9569-7 ... ... / v VI Meta-Modeling: Performance and Information Modeling • Volume 3: High-Level System Modeling: Specification Languages Contents: 1. Specification-Modeling Methodologies for Reactive-System Design. 2. Survey on Languages for Object Oriented Hardware Design Methodologies. 3. VSPEC: A Declarative Requirements Specification Language for VHDL. 4. Communication Protocols Implemented in Hardware: VHDL Generation from Estelle. 5. An Algorithmfor the Translation ofSDL into Synthesizable VHDL. 6. From LOTOS to VHDL. 7. Using An X-Machine to Model a Video Cassette Recorder. Index. 176 pp. ISBN 0-7923-9632-4 • Volume 4: High-Level System Modeling: Specification and Design Methodologies Contents: 1. A System Specification Model and Method. 2. ADEPT: A Unified Environment for End-to-End System Design. 3. The Design Cube: A Model for VHDL Designjlow Representation and its Application. 4. A Novel Approach to Guiding Incremental Specification. 5. An Expert Assistant for Hardware Systems Specification. 6. Integrating Non-Functional Aspects into LOTOS. Index. 192 pp. ISBN 0-7923-9660-x • Volume 5: Hardware Component Modeling Contents: 1. The History of VITAL: VHDL ASIC Library Update. 2. Issues in Efficient Modeling and Acceleration of VITAL Models. 3. Standards for Interoperability and Portability. 4. Abstract Data Types and the Digital System Description and Simulation Environments. 5. Modeling highly flexible and self-generating parameterizable components in VHDL. 6. MELODY: an Efficient Layout-Based Model Generator. 7. Quality Measures & Analysis: a way to improve VHDL models. 8. Modern Concepts ofQ uality and Their Relationship to Design Reuse and Model Libraries. Index. 150 pp. ISBN 0-7923-9686-3 We hope you will enjoy reading this series. We welcome your suggestions and look forward to having you as a contributor. The Series Editors Jean-Michel Berge, France Telecom-CNET, Email: [email protected] Oz Levia, Cadence, Email: [email protected] Jacques Rouillard, ESIM, Email: [email protected] Series & Volume Presentation VII EDITORS Series Editors Jean-Michel Berge -France Telecom -CNET Oz Levia -Cadence Jacques Rouillard -ESIM Principal Advisor to the Editors Jim Armstrong - Virginia Tech Advisory Board Raul Camposano -Synopsys Inc. Hilary Kahn - University ofM anchester Sabine Maerz-Roessel-Siemens AG Zain Navabi - University afTehran Wolfgang Nebel- University afOldenburg Alec Stanculescu -Fintranic Inc. Alain Vachoux -Swiss Federal Institute ofT echnology Ron Waxman -University of Virginia Editorial Board Przemyslaw Bakowski -IRESTE Serge Maginot -Leda S.A. Dave Barton -Intermetrics Inc. Wolfgang Mueller -CADLAB Bill Billowich - VHDL Technology Group Adam Pawlak -ARTEMISllMAG Mark Brown -Compass Bora Prazic -Alcatel Jean-Paul Calvez -IRESTE Paul Scheidt -Synopsys Inc. Steve Carlson -Escalade Jean-Pierre Schoellkopf -SGS-Thomson Simon Curry -Cadence Steve Schultz -Texas Instruments Tedd Corman -EPS Ken Scott -Synopsys Inc. Doug Dunlop -Cadence Venkat Venkataraman -IBM Alain Fonkoua -ESIM Alex Zamfirescu -Intergraph Electronics Andreas Hohl -Synopsys Inc. Roger Zinsner -Speed S.A Michael Hohenbichler -CEC VOLUME PRESENTATION VOLUME 6: META-MODELING:PERFORMANCE AND INFORMATION MODELING Models in system design follow the general tendency in electronics in terms of size, complexity and difficulty of maintenance. While a model should be a manageable -representation of a system, this increasing complexity sometimes forces current CAD-tool designers and model writers to apply modeling techniques to the model itself. Model writers are interested in instrumenting their model, so as to extract critical information before the model is complete. CAD tools designers use internal representations of the design at various stages. The complexity has also led CAD-tool developers to develop formal tools, theories and methods to improve relevance, completeness and consistency of those internal representations. Information modeling involves the representation of objects, their properties and relationships. Performance Modeling When it comes to design choices and trade-offs, performance is generally the final key. However performance estimations have to be extracted at a very early stage in the system design. Performance modeling concerns the set of tools and techniques that allow or help the designer to capture metrics relating to future architectures. Performance modeling encompasses the whole system, including software modeling. It has a strong impact on all levels of design choices, from hardware/software partitioning to the final layout. Chapter 1 addresses the specific problem of communication between performance information and operational specifications. It presents solutions for a variety of problems such as conformance checking and validation of an implementation against its specifications. Chapter 2 illustrates a top-down method that provides the user with the ability to express functional, performance and constraint requirements. The method is based on the MCSE model. This chapter also provides a very useful comparison of the various methods in this field. Jacques Rouillard, Co-Editor ••• f ••• IX x Meta-Modeling: Performance and Information Modeling Information Modelling Specification and formalism have in the past traditionally played little part in the design and development of EDA systems, their support environments, languages and processes. Instead, EDA system developers and EDA system users have seemed to be content to operate within environments that are often extremely complex and may be poorly tested and understood. This situation has now begun to change with the increasing use of techniques drawn from the domains of formal specification and database design. This section of this volume addresses aspects of the techniques being used. In particular, it considers a specific formalism, called information modelling, which has gained increasing acceptance recently and is now a key part of many of the proposals in the EDA Standards Roadmap, which promises to be of significance to the EDA industry. In addition, the section looks at an example ofa design system from the point of view of its underlying understanding of the design process rather than through a consideration of particular CAD algorithms. The third chapter in this volume, "A View of Information Modelling", introduces the concepts of formal specification through information modelling. The particular information modelling formalism selected is EXPRESS, an ISO Standard modelling language. Basic EXPRESS models are developed which show not only that information modelling can be used to capture concepts and semantics in an unambiguous manner, but also that such models can be used to reason about the Universe of Discourse under consideration. The techniques described have been applied to large practical examples, including the specification of the semantics ofVHDL and EDIF. The fourth chapter "A Methodology for the Specification of Transformations between Information Models", considers the issues which arise when related but non-identical information models need some form of 'harmonisation'. The example chosen focuses on an approach to understanding the relationship between the information models of EDIF and CFI DR through the creation of a 'core' model which reflects the capabilities of each of the sources involved. However, the techniques used are not limited to the specific example. As with the preceding chapter, the information modelling language chosen is EXPRESS. The fifth chapter, "Modeling Design Data and Design Processes in the PLAYOUT CAD Framework", changes the emphasis from a formal specification of the design information representation to a model of a complete CAD system. It offers an overall model which is structured into a set of related sub-models whose relationships and dependencies are understood. The result is a system which goes a long way towards ensuring a consistent and well-formed environment. Hilary J. Kahn, Professor at University of Manchester CONTENTS SERIES PRESENTATION v EDITORS VB VOLUME PRESENTATION IX CONTENTS XI CONTRIBUTORS xvn 1. INTEGRATING OPERATIONAL SPECIFICATION WITH PERFORMANCE MODELING 1 by Ambar Sarkar, Ronald Waxman, James P. Cohoon 1.1. Introduction 2 1.2. Design Methodology Supporting Model-Continuity 4 1.3. Integrated Simulation of Statecharts and ADEPT 6 1.4. Functional Timing 7 1.4.1. Timing Constraints Versus Functional Timings 7 1.4.2. Specification of Functional Timings in Statecharts 8 1.4.3. Effects of Ignoring Functional Timing 10 1.5. Performance Annotation 13 1.5.1. Example of Performance Annotation l3 1.5.2. Rules for Performance Annotation 16 XI XII Meta-Modeling: Performance and Information Modeling 1.6. Conformance 18 1.6.1. Rules for Checking Confonnance 18 1.6.2. Confonnance Checking 19 1.6.3. Definition of Confonnance 22 1.6.4. Design Assumptions 24 1.6.5. Properties of rfa and ack Sequences 25 1.6.6. Algorithm 27 1.6.7. Proof of Algorithm DetectConfonnance 28 1.6.8. Orthogonal Sources 30 1.6.9. Algorithm EliminateOrthogonalSources 30 1.7. Results 34 1.7.1. A Brief Overview of Token-Ring 35 1.7.2. Statecharts Description of the Token-Ring 36 1.7.3. ADEPT Model of the Token-Ring 36 1.7.4. Examples 38 1.8. Summary and Conclusions 44 Appendix A: Statecharts 48 A.l States 48 A.2 Transitions 49 Appendix B: ADEPT 50 Appendix C: VHDL 51 Appendix D: Implementation of Methodology 51 2. A SYSTEM-LEVEL PERFORMANCE MODEL AND METHOD 57 by Jean-Paul Calvez 2.1. Introduction 58 2.2. Objective of System Performance Modeling 59 2.2.1. Tenninology Clarification 59 2.2.2. Design Process and Perfonnance Evaluation 60 2.2.3. Classification of System-Level Models 62 2.3. Related Works 63 2.4. Presentation of the Method 65 2.5. Criteria and Qualities of a Performance Model 67