Controller area network: a formal case study

We present a formal analysis of a Controller Area Network (CAN) controller using the Z specification language. It is a step in the evaluation of functional and performance properties of CAN applications. We first show how an external view of CAN controller functionalities can be held in Z. Z is based on set theory and first order logic and is very expressive: a unique notation allows the specification of data structures and operations. An internal view as also given and analyzed. Validation of the CAN controller specification is done and a property is shown; we demonstrate that this specification implements the satisfaction of the highest priority message being transmitted first.