Embedded Systems Design: A Unified Hardware/Software Introduction 1 Introduction to embedded Systems

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 2 Outline Embedded systems overview –What are they? Design challenge – optimizing design metrics Technologies –Processor technologies –IC technologies –Design technologies

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 3 Embedded systems overview Computing systems are everywhere Most of us think of “desktop” computers –PC’s –Laptops –Mainframes –Servers But there’s another type of computing system –Far more common...

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 4 Embedded systems overview Embedded computing systems –Computing systems embedded within electronic devices –Hard to define. Nearly any computing system other than a desktop computer –Billions of units produced yearly, versus millions of desktop units –Perhaps 50 per household and per automobile Computers are in here... and here... and even here... Lots more of these, though they cost a lot less each.

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 5 A “short list” of embedded systems And the list goes on and on Anti-lock brakes Auto-focus cameras Automatic teller machines Automatic toll systems Automatic transmission Avionic systems Battery chargers Camcorders Cell phones Cell-phone base stations Cordless phones Cruise control Curbside check-in systems Digital cameras Disk drives Electronic card readers Electronic instruments Electronic toys/games Factory control Fax machines Fingerprint identifiers Home security systems Life-support systems Medical testing systems Modems MPEG decoders Network cards Network switches/routers On-board navigation Pagers Photocopiers Point-of-sale systems Portable video games Printers Satellite phones Scanners Smart ovens/dishwashers Speech recognizers Stereo systems Teleconferencing systems Televisions Temperature controllers Theft tracking systems TV set-top boxes VCR’s, DVD players Video game consoles Video phones Washers and dryers

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 6

7 Automotive embedded systems Today’s high-end automobile may have 100 microprocessors: –4-bit microcontroller checks seat belt; –microcontrollers run dashboard devices; –16/32-bit microprocessor controls engine.

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 8 BMW 850i brake and stability control system Anti-lock brake system (ABS): pumps brakes to reduce skidding. Automatic stability control (ASC+T): controls engine to improve stability. ABS and ASC+T communicate. –ABS was introduced first---needed to interface to existing ABS module.

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 9 BMW 850i, cont’d. brake sensor brake sensor brake sensor brake sensor ABS hydraulic pump

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 10 Some common characteristics of embedded systems 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

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 11 Supported by a wide array of processors Cost sensitive Uses real-time operating systems(RTOS) Must operate under extreme environmental conditions Fewer system resources Object code stored in ROM Software failure is much more severe

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 12 Cost Sensitivity Usually embedded systems are manufactured in bulk Limited functionality(Size,Power,price) Powerful embedded processors Above requirements are found in cellular phones(DSP processors)

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 13 Extreme Environmental conditions Runs everywhere anytime under any condition It is not good practice to consider following aspects during testing or packaging: Heat budget Slow down the clock Change code(Optimize)

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 14 Real-Time constraints  Time sensitive constraints(Soft real-time) Due to some technical limitations task will take longer time than the design goal. Instead of printing three pages per minute, two pages are printed.  Time critical(Hard real-time) Time critical task should take place within a time frame, available between monitored or measured events. If the task is not completed before the next event arrives, the function controlled by that task fails.

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 15 An embedded system example -- a digital camera Microcontroller CCD preprocessorPixel coprocessor A2D D2A JPEG codec DMA controller Memory controllerISA bus interfaceUARTLCD ctrl Display ctrl Multiplier/Accum Digital camera chip lens CCD Single-functioned -- always a digital camera Tightly-constrained -- Low cost, low power, small, fast Reactive and real-time -- only to a small extent

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 16 Design challenge – optimizing design metrics Obvious design goal: –Construct an implementation with desired functionality Key design challenge: –Simultaneously optimize numerous design metrics Design metric – A measurable feature of a system’s implementation –Optimizing design metrics is a key challenge

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 17 Design challenge – optimizing design metrics Common metrics –Unit cost: the monetary cost of manufacturing each copy of the system, excluding NRE cost –NRE cost (Non-Recurring Engineering cost): The one-time monetary cost of designing the system –Size: the physical space required by the system –Performance: the execution time or throughput of the system –Power: the amount of power consumed by the system –Flexibility: the ability to change the functionality of the system without incurring heavy NRE cost

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 18 Design challenge – optimizing design metrics Common metrics (continued) –Time-to-prototype: the time needed to build a working version of the system –Time-to-market: the time required to develop a system to the point that it can be released and sold to customers –Maintainability: the ability to modify the system after its initial release –Correctness, safety, many more

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 19 Microprocessor varieties Microcontroller: includes I/O devices, on-board memory. Digital signal processor (DSP): microprocessor optimized for digital signal processing. Typical embedded word sizes: 8-bit, 16-bit, 32-bit.

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 20 Application examples Simple control: front panel of microwave oven, etc. Canon EOS 3 has three microprocessors. –32-bit RISC CPU runs autofocus and eye control systems. Analog TV: channel selection, etc. Digital TV: programmable CPUs + hardwired logic.

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 21

Embedded Systems Design: A Unified Hardware/Software Introduction 22 In the 21 st Century, internet-enabled appliances will dominate the technology space - paving the way for electronic maintenance. and beyond Technology Overview DecadePredominant Technology ’60sMainframes ’70sMini Computers ’80sPersonal Computers ’90s Internet for people 2000Internet for Devices Source: IDC e-Vending Vending Management from the Desktop

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 23 We provide real-time interactivity between man and machines over the Net Devices World Sdn Bhd Your Embedded Internet Partner Recognizing the potential of the Embedded Internet Space, we have pioneered a cutting edge e-Maintenance application complete with hardware and software solution. DevicesWorld.net An integrated e-Maintenance portal with comprehensive software solutions for various industries. Internet Access Devices A comprehensive range of hardware to Internet-enable your legacy appliances. You have a choice of wired or wireless Internet connectivity. e-Vending Vending Management from the Desktop

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 24 Internet Stock Level Report Machine Status Report Dispatch Activity Log Vending Activity Log DevicesWorld.net Server Operator’s Office Internet Automatic Alerts ! Pager Phone e-Vending Vending Management from the Desktop Internet Gateway

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 25 Cold Drink VendorSnack Food Vendor Hot Drink Vendor Internet Gateway Slave Interne t Telephone Line GSM One Gateway 16 Machines 1000m Apart DevicesWorld.net e-Vending Vending Management from the Desktop

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 26 Internet Gateway  Built-in Modem  5 Digital Inputs  5 Analogue Inputs  2 Digital Outputs Slave  Plug & Play  5 Digital Inputs  5 Analogue Inputs  2 Digital Outputs Hardware Features e-Vending  Event - driven Dialup  Automatic Health Check  On Demand Connection  Password Protection  Automatic Configuration  Local Data Logging  Data Encryption

Embedded Systems Design: A Unified Hardware/Software Introduction, (c) 2000 Vahid/Givargis 27 Summary Embedded systems are everywhere Key challenge: optimization of design metrics –Design metrics compete with one another A unified view of hardware and software is necessary to improve productivity Three key technologies –Processor: general-purpose, application-specific, single-purpose –IC: Full-custom, semi-custom, PLD –Design: Compilation/synthesis, libraries/IP, test/verification