10:40 - 11:15  Paper 2

Exactly when do you need real-time?

Garry Bleasdale, Field Applications Engineer, QNX Software Systems

Does your next embedded project need a real-time operating system? It is a good question, given the speed of today's processors and the availability of real-time patches for Linux, Windows, and other general-purpose operating systems. As it turns out, many embedded applications still need a "hard" real-time operating system to function correctly, though the issue isn't considered during the initial product. This session explores where and why real-time is required, various definitions of real-time, and the effect of the operating system on a real-time design. We will also discuss design methods and programming-language features appropriate for real-time; identify operating-system requirements for real-time (e.g. pre-emptible kernel, priority inheritance, nested interrupts); and explore the tradeoffs between using a general-purpose OS or an RTOS. Practical issues, such as setting appropriate task priorities and avoiding high-frequency interrupts, will also be covered.