1 The Future of Software Architecture: Special Issues in Embedded, Real-time Systems Carolyn Boettcher, Richard Falcioni Raytheon Company, Electronic Systems El Segundo, CA.

2 Embedded, Real-time System Architecture Characteristics From perspective of Raytheon products with hard, real-time requirements (e.g. airborne radar) - Software is constrained by interfaces with various specialized hardware devices - Correctness of results is dependent on timeliness - Systems have a long life time ( years) - Software architecture must be evolvable to incorporate new hardware technologies and provide new functionality Domain-specific software architectures are critical for creating future affordable, adaptable, software-intensive products

3 Experience with Airborne Radar Architecture Over last 15 years, Raytheon (previously Hughes Aircraft) developed a common software architecture for airborne radar - architecture was closely tied to custom processing architecture - difficult and not cost effective to port to new generation of processors It is highly desirable to be able to insert new processors into systems with minimal software impact - throwaway HW, but SW goes on forever Need a software representation that is independent of hardware, but facilitates mapping onto alternative parallel processing architectures Desire plug-and-play to interface with a variety of specialized hardware devices - sensors, communications, multi-media, virtual reality displays

4 A Comparison of Desktop and Combat System Topologies

5 Plug and Play in Workstation Resource Management

6 Example - Resource Contention in Real-time Plug and Play Systems

7 Issues in Evaluating Real-time, Embedded Architecture Predict system performance Support system evolution over a long life time Resolve resource conflicts to provide predictable performance within a plug-and-play paradigm These issues must be resolved if architectural advances from desktop systems are to be applied to real-time, embedded systems