1 / 12

Chapter 1

Chapter 1. Embedded And Real-Time System Department of Computer Science Hsu Hao Chen Professor Hsung-Pin Chang. Outline. What is an embedded system ? Characteristics of embedded systems Real-time systems concept Real-time operating systems and real-time kernels

jconde
Download Presentation

Chapter 1

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. Chapter 1 Embedded And Real-Time System Department of Computer Science Hsu Hao Chen Professor Hsung-Pin Chang

  2. Outline • What is an embedded system? • Characteristics of embedded systems • Real-time systems concept • Real-time operating systems and real-time kernels • Processes, tasks, and threads • Architecture of real-time systems

  3. What is an embedded system? • For practical purposes • Embedded system consisting of a compact, fast, and extremely reliable operating system • Microprocessor located inside a device • Embedded system is a collection of programs that run under operating system

  4. Characteristics of embedded systems(1/2) • Virtually all kinds of computing systems • Temporal determinism • Time required to process any task is finite and predictable • Less concerned with average response time than worst-case response time • Must have a guarantee on the upper time limit

  5. Characteristics of embedded systems(2/2) • It is typically encapsulated by the hardware it controls, so end-users are unaware of its presence • It is actually a computer system that does not have the outward appearances of a computer system.

  6. Real-time systems concept • Operate within specified time constraints • System must respond to inputs or events within prescribed time limits • Real-time constraints: • Hard Real-Time • Example: air traffic control system. • Soft Real-Time • Example: PS2

  7. Real-time operating systems and real-time kernels RTOS kernel Other RTOS services Kernel

  8. Processes, tasks, and threads

  9. Architecture of real-time systems(1/2) • Threads are process two common architecture • Control loop with polling • Polling of the kernel executes an infinited loop Advantage: easy to implement Disadvantage: difficult to give threads with critical fast access to the processor

  10. Architecture of real-time systems(2/2) • Preemptive scheduling method • ThreadX use is preemptive scheduling method Advantage: priority solved critical fast access to the processor

More Related