Model-Based Embedded Real-Time Software Development

Embedded real-time systems are tightly coupled with the physical world. This tight coupling imposes parafunctional requirements (such as timeliness, jitter, faulttolerance, and security) that go beyond functional (logical) behaviors. Unfortunately, modern programming approaches do not facilitate the independent encoding of functional and para-functional behaviors. In this paper, we argue that (a) a model of embedded software must be complemented by an appropriate model of the underlying hardware platform, (b) a model-based paradigm can be used to capture para-functional behaviors independent of functional aspects, (c) para-functional behaviors can be constituted from multiple dimensions, each of which can be manipulated by a user independent of others, and (d) the implementation impact of changes in one dimension must be automatically reflected along other dimensions. Time Weaver, a tool developed at Carnegie Mellon University under the DARPA MoBIES program, supports these capabilities. These three capabilities enable (i) clean reuse and/or automatic generation of all parafunctional code (ii) real-time scheduling analysis and verification and (iii) (later) automated test-vector generation. 1 Models Beyond Programming