Towards standard-based specification and design of embedded real-time systems

Real-time Systems and embedded systems in particular have, until recently, been built as works of art. Standard hardware components only are now being used and scalable standardized operating systems are being built. There have been many attempts to simplify the design of these systems through the use of standard mechanisms and components, but many have failed due to the specific nature of their applications. A standard-based approach to the specification of hardware and software configurations of embedded real-time systems is described. It is based on the DIN standard 66 253, Part 3: PEARL for Distributed systems and customized for use in hard real-time embedded applications-"Specification PEARL". A specification language is presented in its BNF notation as well as the graphical notation with the same expressive power which was derived from it. The approach supports top down refinement. The specifications allow HW/SW co-design, consistency checking and provide a good foundation for the design phase of the system development cycle. In fact the design of software can be introduced from the specification where abstract software collections are identified and associated with stations of the system in a natural way.