real-time operation

Real-time systems are computers embedded in devices like cars, aircraft, and manufacturing lines to control processes instantly. These systems often perform tasks at fixed intervals, such as gathering sensor data and generating control signals. Scheduling theory is used to manage these tasks efficiently.1

Real-time systems can be categorized as "hard" or "soft" based on their deadlines. Hard real-time systems, like aircraft control systems, must guarantee schedules to handle all events, as missed deadlines can be fatal. Soft real-time systems, such as airline reservation systems, can tolerate occasional missed deadlines without catastrophic consequences.2

Features common in modern CPUs and operating systems, like pipelines and virtual memory, can introduce unpredictable delays, making them unsuitable for hard real-time applications. Therefore, embedded processors and their operating systems are often simpler to ensure reliability.2