Requirements definition languages for real-time embedded systems
Paul Clements · 1994
This work investigates requirements specification languages for embedded hard-real-time systems. A new high-level domain-independent language is presented, which is intuitive enough to be clear to developers, yet formal enough to provide a basis for safety assertion verification, program synthesis, and simulation. The language is based on the concept of scenarios, which are partial orders of events. The language is demonstrated on three authentic systems chosen from the avionics domain. An algorithm is presented, tempered with practical heuristics, for translating a scenario into a semantically equivalent Modechart specification with desirable structural properties. Algorithms are also presented for translating specifications rendered in a state-table notation into Modechart. Thus, a suite of interchangeable requirements languages is produced, allowing specifiers to use the language most amenable to the situation at hand, while being able to take advantage instantly of an analysis procedure (such as Modechart simulation or verification) that is native to any language in the suite.