Verifying Part of the ACCESS.bus Protocol using PVS

. Based on a compositional framework for the formal specification of distributed real-time systems, we present a method for protocol verification. To be able to deal with realistic examples, the method is supported by the interactive proof checker PVS. In this paper we illustrate our approach by a protocol of the ACCESS.bus which is used for the communication between a computer host and its peripheral devices (e.g., keyboards, mice, joysticks, etc.). The bus supports dynamic reconfiguration while the system is operating. We specify and verify a safety property and a real-time progress property of this industrial example. 1 Introduction In previous work we have addressed the formal specification and verification of distributed real-time systems (see, e.g., [Hoo91]). A framework based on Hoare triples has been applied to several examples such as a water level monitoring system [Hoo93] and a chemical batch processing system [Hoo94c]. In the current paper we only consider the bas..