Software Engineering Institute

The purpose of this paper is to provide the reader with some technical information and observations ADA source code, and measurement results based on experimentation with respect to developing a real-time periodic task dispatcher in ADA. In this context, a periodically scheduled task set implies that each task in the set is executed at its own fixed frequency; a periodic task dispatcher is a software component that schedules the individual tasks at their implied runtime frequency. The results presented here are specific to a MicroVAX-II/VAXELN 2.3 target system, the VAXELN 1.1 ADA compiler, and a KWV11-C programmable real-time clock. Specifically, these results provide answers to the question: How can one achieve the effect of scheduling a set of periodic ADA tasks when the runtime frequency of some of the individual tasks is less than the clock-cycle frequency supported by an ADA runtime implementation?