Constructing time-critical embedded systems: Decide before runtime

Abstract

Summary form only given. The hardware and software architectures of time-critical embedded systems are becoming too complex. As a consequence, the timing of these systems is difficult to understand and proofs about temporal correctness are hard if not impossible to obtain. We argue that we should not follow the current trends and make computers more and more complex. Instead we should design and use hardware and software architectures that are as simple as possible. When using these architectures, one should take as many decisions as possible before runtime, thus minimizing the number of scenarios in which the timing of the computer system is situation-dependent. We introduce hardware and software strategies that are smart enough to eliminate dynamic run-time decisions, thus improving the time-predictability of embedded computer systems. Using these strategies makes the timing behavior of computer systems easy to understand. Thus proofs for temporal correctness become almost trivial.