1 / 7

Embedded Operating Systems

Embedded Operating Systems.

lynda
Télécharger la présentation

Embedded Operating Systems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Embedded Operating Systems “Embedded System: A combination of computer hardware and software, and perhaps additional mechanical or other parts, designed to perform a dedicated function. In many cases, embedded systems are part of a larger system or product, as in the case of an antilock braking system in a car.” Text. P. 574 Chapter 13 Embedded Systems

  2. Embedded systems • Characteristics • Small to large systems – • different costs, different requirements • Strict to “relaxed” requirements in terms of • Safety, reliability, real-time, flexibility, legislation • Short to long life times • Different environmental conditions • Different application characteristics • Response time, computing or interface needs Chapter 13 Embedded Systems

  3. Some types of devices • Automotive • Consumer electronics • Industrial control • Medical • Office automatiion Chapter 13 Embedded Systems

  4. Embedded Systems OS • Simple embedded systems may have no OS, or some few OS commands integrated with other software • Typically, embedded system have special-purpose OS • Sample OS – eCos, QNX, TinyOS, or VxWorks Chapter 13 Embedded Systems

  5. Embedded OS characteristics • Time constraints • Reactive to external events – interrupt driven • Configurability if OS must handle different types of devices • I/O device flexibility • Large range in i/o types • Limited protection mechanisms • Software rarely added after system is marketed Chapter 13 Embedded Systems

  6. Embedded OS characteristics • Small • Fast context switch (thread or process) • Priority, preemptive scheduling • Dispatcher & low level scheduler integrated • Fast response to interrupt • Little or no disabling of interrupts • Real memory with partitions • Data may be kept in memory Chapter 13 Embedded Systems

  7. Using a commercial OS • Linux, Windows, and FreeBSD have all been used with embedded systems- users prefer well known interface– but at a cost • Slower, less predictable, must be modified and optimized to meet real-time demands of embedded system • Commercial OS schedules for average case; embedded OS schedules for worst case Chapter 13 Embedded Systems

More Related