Hard real-time prototyping of SA/RT specifications

Preliminary results with an experimental prototyping toolset are reported. The Espex toolset is designed for graphics-based animation and real-time execution of Ward & Mellor Structured Analysis for Real-Time Systems (SA/RT) specifications. The computational model underlying the toolset is based on mapping SA/RT modeling elements to high level Petri nets. For execution of these SA/RT models a variety of scheduling algorithms have been developed. The authors focus their attention on experiments with deadline-based scheduling. They have built two tools for execution of SA/RT models: a graphical animator and a hard real-time prototyper tool. The graphical animator tool is used for building the model, for logically validating the model, and for attaching physical attributes to the model. The hard real-time prototyper tool is used for execution of the model at real-time speeds with either a real or a simulated environment