ICS 180 Spring Embedded Systems. Introduction: What are Embedded Systems and what is so interesting about them?

Transcription

1 ICS 180 Spring 1999 Embedded Systems Introduction: What are Embedded Systems and what is so interesting about them? A. Veidenbaum Information and Computer Science University of California, Irvine.

2 Outline Course objectives and plan What is an embedded system? Embedded system market trends Characteristics of embedded systems Embedded system requirements Classification of embedded systems 2

3 Course Objectives Develop an understanding of the technologies behind the embedded computing systems major hardware software components, their interaction real-time software, programming issues, languages Do a lot of hands-on development using simple robots Plan robotic arm, rover understanding the non-computer components and their control C and Basic programming Spend more time in the lab and doing assignments and project than in lectures Relate what was learned in class to the lab Be able to say on your resume: Experience with embedded system development 3

4 Embedded Systems An embedded system employs a combination of hardware & software (a computational engine ) to perform a specific function; is part of a larger system that may not be a computer ; works in a reactive and time-constrained environment. Software is used for providing features and flexibility Hardware is used for performance (& sometimes security) DSP Code Application Specific Gates Analog I/O Processor Cores Memory 4

5 Disadvantages New Hrdw/Sftw development required Higher HW/software development overhead design, compilers, debuggers,... May result in delayed time to market! 6

6 Embedded Systems:Applications Consumer electronics, e.g., cameras, camcorders,... Consumer products, e.g., washers, microwave ovens,... Automobiles (anti-lock braking, engine control,...) Industrial process controllers & avionics/defense applications Computer/Communication products, e.g., printers, FAX machines,... Emerging multimedia applications & consumer electronics e.g., cellular phones, personal digital assistants, videoconferencing servers, interactive game boxes, TV set-top boxes,... Multimedia => Increasing computational demands, and increased reliance on VLSI, HW/SW integration. 7

7 Example ES (I): Dryer (from Siemens Web page) 8 Courtesy: K-S Chung, UIUC

8 Example ES (II): Digital Camera (from LSI Logic Web page) Courtesy: K-S Chung, UIUC 9

9 Diversity in Embedded Computing Pocket remote control RF transmitter 100 KIPS, crush-proof, long battery life Software optimized for size Industrial equipment controller 1 MIPS, safety-critical, 1 MB memory Software control loops Military signal processing 1 GFLOPS, 1 GB/sec IO, 32 MB Software for high performance. Rugged construction, wide environmental tolerance 10

10 Market facts Market size for embedded systems: $31 B General-purpose computing $46.5 B Microcontroller market: $4.6 B, +18% AGR versus +10 % AGR for GP processors Market watchers tell us (in 1997) that: ECS market will surpass computing market sometime before this decade is out 11

11 Driving forces Computing technologies are proliferating to non-computing domains portable units with significant data & control ops. medical instrumentation & imaging, information appliances, communications... Increasing need for product personalization Application domains and user differentiation Device programmability Competitive pressures of commodity markets Time to market (TTM), Time to money (TT$), Product lines, Product differentiation,... 12

12 Environ -ment ASIC Processor DSP Code Embedded systems design: Major subtasks Analog I/O Memory Modelling the system to be designed, and experimen with algorithms involved; Refining (or partitioning ) the function to be implemented into smaller interacting pieces; HW-SW partitioning: Allocating elements in the refined model to either (1) HW units, or (2) SW running on custom hardware or a general microprocessor. Scheduling the times at which the functions are execut This is important when several modules in partition share a single hardware unit. Mapping (Implementing) a functional description into (1) software th runs on a processor or (2) a collection of 14 custom, semi-custom, or commodity HW.

13 What is HW/SW Codesign? Traditional Design SW and HW partitioning is decided at an early stage, and designs proceed separately from then onward. CAD today addresses synthesis problems at a purely hardware level: ECS use diverse (commodity) components up, DSP cores, network and bus interfaces, etc. Codesign A flexible design strategy, wherein the HW/SW designs proceed in parallel, with feedback and interaction occurring between the two as the design progresses. Final HW/SW partition/allocation is made after evaluating trade-offs and performance of options. 15

14 Embedded System Design Requirements: Codesign? Goal: Improved time to market (for a given function) with acceptable performance (speed, power, cost, reliability,...) and product differentiation Traditional productivity metric Gates delivered per day Lines of software delivered per day New productivity metric of relevance Functionality delivered in a market window Requires better ways to design systems that have a heterogeous mix of hardware and software subsystems. => New design paradigms, techniques, & tools. 16

15 Disciplines used in embedded system design The design of embedded systems draws upon several disparate disciplines in CS and EE. Application domain (Signal processing,...) Software engineering (Programming Languages, Compilers) For implementing the software components; this can be a major component of several systems. VLSI (computer aided) design For implementing the custom and semi-custom hardware components. Networked, Parallel/Distributed system design since many embedded systems and multiprocessors are structured as a network of communicating processors; the network may be loosely coupled or tightly coupled. Real-time systems (Hard- & soft- real time systems) 20