A specification methodology by a collection of compact properties as applied to the Intel® Itanium™ processor bus protocol

Abstract

In practice, formal specifications are often considered too costly for the benefits they promise. Specifically, interface specifications such as standard bus protocol descriptions are still documented informally, and although many admit formal versions would be useful, they are dissuaded by the time and effort needed for development. We champion a formal specification methodology that attacks this costvalue problem from two angles. First, the framework allows formal specifications to be feasible for signal-level bus protocols with minimal effort, lowering costs. And second, a specification written in this style has many different uses, other than as a precise specification document, resulting in increased value over cost. This methodology allows the specification to be easily transformed into an executable checker or an simulation environment, for example. In an earlier paper, we demonstrated the methodology on a widelyused bus protocol. Now, we show that the generalized methodology can be applied to more advanced bus protocols, in particular, the Intel® ItaniumTM Processor bus protocol. In addition, the paper outlines how writing and checking such a specification revealed interesting issues, such as deadlock and missed data phases, during the development of the protocol.