VAXELN Experimentation: Programming a Real-Time Periodic Task Dispatcher Using VAXELN Ada 1.1

摘要

The purpose of this paper is to provide the reader with some technical information and observations, Ada source code, and measurement results based on experimental with respect to developing a real-time periodic task dispatcher in Ada. The results presented here are specific to a uVAX-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. The Ada Embedded Systems Testbed Projects investigate approach promotes three typical stages to developing real-time systems: benchmarking; experimentation and prototyping; and designing, coding, and testing an application. To study the performance characteristics of Ada cross-compilers, we are running several existing benchmark test suites to explore the time, space, and capacity constraints associated with individual Ada features. (KR)