Embedded System Design - Chapter 1: Embedded System Overview

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1. 8/9/2016 ĐẠI HỌC QUỐC GIA TP.HỒ CHÍ MINH TRƯỜNG ĐẠI HỌC BÁCH KHOA KHOA ĐIỆN-ĐIỆN TỬ BỘ MÔN KỸ THUẬT ĐIỆN TỬ Embedded System Design Chapter 1: Embedded System Overview 1. What is an embedded system? 2. Embedded system models 3. Embedded system features 4. Real-time embedded system 1 1. What’s an Embedded System? • Embedded systems = – information processing systems that interact with physical processes and are embedded into a larger product • Two types of computing – Desktop – produced millions/year – Embedded – billions/year • Non‐Embedded Systems – PCs, servers, and notebooks • The future of computing! – Automobiles, entertainment, communication, aviation, handheld devices, military, medical equipment Bộ môn Kỹ Thuật ĐiệnTử - ĐHBK Chapter 1 2 1
2. 8/9/2016 Embedded System Examples • A car door mechanism – Window stall sensor, door sensor – Window motor, lock actuator – Window control buttons Bộ môn Kỹ Thuật ĐiệnTử - ĐHBK Chapter 1 5 Embedded System Examples • The Derbot Vehicle – Two microswitch bump detectors – an untrasound detector – Two light sensors – a servo actuator • Derbot is powered from six AA Alkaline cells Bộ môn Kỹ Thuật ĐiệnTử - ĐHBK Chapter 1 6 3
3. 8/9/2016 3. Embedded System Features Components of Embedded Systems Clock Display Power Embedded software Peripherals ROM Embedded Processor Buttons RAM Sensors A/D I/O Actuators • Embedded processor is a heart of the embedded system: – micro‐processor: 8086, ARM7, ARM9 – micro‐controller: 8051, ARM Cortex‐M, PIC16F, 68HC11, Bộ môn Kỹ Thuật ĐiệnTử - ĐHBK Chapter 1 9 3. Embedded System Features • Memory – ROM: embedded program – RAM: processing data • Embedded program – OS / non‐OS supported – realtime / non‐realtime – timer, interrupt, serial port • Clock: – crystal • Power: – +5V / +3.3V / +2.5V Bộ môn Kỹ Thuật ĐiệnTử - ĐHBK Chapter 1 10 5
4. 8/9/2016 An embedded system example A digital camera Digital camera chip CCD CCD preprocessor Pixel coprocessor D2A A2D lens JPEG codec Microcontroller Multiplier/Accum DMA controller Display ctrl Memory controller ISA bus interface UART LCD ctrl • Single-functioned always a digital camera • Tightly-constrained Low cost, low power, small, fast • Reactive and real-time: needs to respond to the pressing of buttons by a user Bộ môn Kỹ Thuật ĐiệnTử - ĐHBK Chapter 1 13 3. Embedded System Features 3 Common Characteristics: • Single‐functioned – Executes a single program, repeatedly • Tightly‐constrained – Low cost, low power, small, fast, etc. • Reactive and real‐time – Continually reacts to changes in the system’s environment – Must compute certain results in real‐time without delay Bộ môn Kỹ Thuật ĐiệnTử - ĐHBK Chapter 1 14 7
5. 8/9/2016 4. Real‐time Embedded Systems • Definition: – A real‐time system is one that must process information and produce a response within a specified time – Any system in which the time at which output is produced is significant. • Almost embedded systems are real‐time Bộ môn Kỹ Thuật ĐiệnTử - ĐHBK Chapter 1 17 4. Real‐time Embedded Systems • Hard real‐time system: – missing a deadline is a total system failure. – Many of these systems are considered to be safety critical – In general there is a cost function associated with the system Bộ môn Kỹ Thuật ĐiệnTử - ĐHBK Chapter 1 18 9
6. 8/9/2016 Quiz 1. What is an embedded system? 2. What are embedded system features? 3. What are issues of embedded system design? 4. What are five basic requirements of an embedded system? 5. What are eight dimension of quality of an embedded system? 6. What are common characteristics of an embedded system? 7. What is real‐time issue of embedded system design? Give example. 8. What is the most importance part of an embedded system? 9. What are differences between hard and soft real‐time systems? Bộ môn Kỹ Thuật ĐiệnTử - ĐHBK Chapter 1 21 11