Analyzing Specifications for Delay-Insensitive Circuits

We present the XDI Model for specifying delay-insensitive circuits, that is, reactive systems that correctly exchange signals with their environment in spite of unknown delays incurred by the interface. XDI specifications capture restrictions on the communication between circuit and environment, treating both parties equally. They can be visualized as state graphs where each arrow is labeled by a communication terminal and each state by a safety/progress label. We investigate various properties that can be extracted from XDI specifications: automorphisms, environment partitions, autocomparison matrix, and classifications of choice, order dependence, and nondeterminism. We introduce a distinction between static and dynamic output nondeterminism, capturing the difference between design freedom and arbitration. Determining specification properties is useful for validation and design. Acknowledgment This work has been supported by the European Commission under Working Group ACiD-WG (Esprit Nr. 21049) as part of the Fourth Framework. Copyright Information c © Copyright 1998 IEEE. Published in the Proceedings of ASYNC’98, March 30–April 2, 1998 in San Diego, California, pages 172–183. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works, must be obtained from the IEEE. Contact: Manager, Copyrights and Permissions / IEEE Service Center / 445 Hoes Lane / P.O. Box 1331 / Piscataway, NJ 08855-1331, USA. Telephone: + Intl. 908-562-3966. Analyzing Specifications for Delay-Insensitive Circuits Tom Verhoeff Faculty of Mathematics and Computing Science Eindhoven University of Technology, The Netherlands Abstract We present the XDI Model for specifying delayinsensitive circuits, that is, reactive systems that correctly exchange signals with their environment in spite of unknown delays incurred by the interface. XDI specifications capture restrictions on the communication between circuit and environment, treating both parties equally. They can be visualized as state graphs where each arrow is labeled by a communication terminal and each state by a safety/progress label. We investigate various properties that can be extracted from XDI specifications: automorphisms, environment partitions, autocomparison matrix, and classifications of choice, order dependence, and nondeterminism. We introduce a distinction between static and dynamic output nondeterminism, capturing the difference between design freedom and arbitration. Determining specification properties is useful for validation and design.We present the XDI Model for specifying delayinsensitive circuits, that is, reactive systems that correctly exchange signals with their environment in spite of unknown delays incurred by the interface. XDI specifications capture restrictions on the communication between circuit and environment, treating both parties equally. They can be visualized as state graphs where each arrow is labeled by a communication terminal and each state by a safety/progress label. We investigate various properties that can be extracted from XDI specifications: automorphisms, environment partitions, autocomparison matrix, and classifications of choice, order dependence, and nondeterminism. We introduce a distinction between static and dynamic output nondeterminism, capturing the difference between design freedom and arbitration. Determining specification properties is useful for validation and design.