Using ´parallel automaton´ as a single notation to specify, design and control small computer based systems

Presents a methodology for using a \´parallel automaton\´ to set up the requirements, to specify and to execute small computer-based systems (CBSs). A parallel automaton is an extended form of the Mealy machine. It handles a finite set of events (variable conditions or clock conditions) which can occur in parallel, and performs a finite set of actions which can be carried out in parallel. In the parallel automaton, there is no concept of a "global state" as in the Mealy machine. Instead, to each action and to each event is associated a "private state" representing their occurrence in the application. Nevertheless, the number of event/action private states is also finite. This single notation (a parallel automaton with private states) can be used to describe requirements and specifications in the same way. Moreover, these two descriptions can be connected. The aims of the application can be described using a parallel automaton as a black box with initial inputs and final outputs. This parallel automaton can then be refined and enhanced with intermediate conditions and actions to obtain detailed requirements. By successive refinements and enhancements, a sufficiently detailed executable specification can be derived. We present this methodology through a simple CBS example for requirements and specifications using the parallel automaton notation. We then give an architecture of a virtual machine that we have built to execute such a parallel automaton on a network.