Graphics Based Prototyping of Real-Time Systems

This paper presents the Espex tool which has been developed in the Espex project at VTT. The Espex tod is a graphical simulation and prototyping tool for Structured Analysis for Real-Time Systems (SA-RT). Petri net like Espex-graphs are used for modeling a system. The presentation concentrates on the simulation of a task model. A pre-emptive priority based scheduling is simulated in the execution of a task modd. Experiences on using the Espex tool in a real example is also reparted. The Espexenvironment is implemented in the Smalltalk-80 programming environment in Sun3 and MacIntoshII workstations.