An Embedded System is a Special

8/2/2019 An Embedded System is a Special

1/9

An embedded system is a special-purpose computer system, which is completely encapsulated by the device it

controls. An embedded system has specific requirements and performs pre-defined tasks, unlike a general-purpose

personal computer.

An embedded system is a programmed hardware device. A programmable hardware chip is the 'raw material' and it

is programmed with particular applications. This is to be understood in comparison to older systems with full

functional hardware or systems with general purpose hardware and externally loaded software. Embedded systems

are a combination of hardware and software which facilitates mass production and variety of application

A combination of computer hardware and software, and perhaps additional mechanical or other parts, designed to

perform a dedicated function.

In some cases, embedded systems are part of a larger system or product, as in the case of an anti lock braking systemin a car.

* EMBEDDED SYSTEM is a combination of SOFTWARE and HARDWARE.

* An Embedded system is a system, that has a computing device embedded into it.

* These are the controllers, processors, arrays or other hardware using dedicated (embedded) logic or programming

(code) called firmware or a microkernel

* Embedded systems are designed around a C which integrates Memory & Peripherals

Embedded systems: What are they?A special purpose computer built into a larger device Special-purposeEmbedded systems have a (more or less) well-defined purpose Contrast with: general purpose computers (PCs etc)

Built into a larger deviceEmbedded systems are (usually) part of a larger device, augmenting its capabilities

WHY EMBEDDED SYSTEMS

It is EMBEDDED because the Micro Controller is inside some other system.For Example a Micro Controller is EMBEDDED into your TV, car, or applianceThe consumer need not think about how to make it perform or process


2/9

* Avoids lots of Electronics Components

* Built in rich Features

* Reduces the cost, space

* Less Down Time for Maintenance

* Probability of Failure is reduced

* Easy interface with Computers

CHARACTERISTICS OF AN EMBEDDED SYSTEM

Sophisticated functionality

Real-Time Operation

Low Manufacturing Cost

Low Power Consumption

Eliminates Necessity of Complex Circuitry

Smarter Products

Smaller Size

User Friendly

State of the Art Technology

Four General Embedded Systems Types

General Computing

Applications similar to desktop computing, but in an embedded package Video games, set- top boxes, wearable computers, automatic tellers

Control Systems

Closed- loop feedback control of real- time system Vehicle engines, chemical processes, nuclear power, flight control

Signal Processing

Computations involving large data streams Radar, Sonar, video compression

Communication & Networking

Switching and information transmission Telephone system, Internet

FEATURES OF AN EMBEDDED SYSTEM

Real-Time Operation

Reactive: computations must occur in response to external events Correctness is partially a function of time

Small Size, Low Weight


3/9

Hand- held electronics and Transportation applications -- weight costs money

Low Power

Battery power for 8+ hours (laptops often last only 2 hours)

Harsh environment Heat, vibration, shock, power fluctuations, RF interference, lightning, corrosion

Safety- critical operation

Must function correctly and Must not function in correctly

Extreme cost sensitivity

EMBEDDED SYSTEMS COMPONENTS

* MICRO CONTROLLERS (C)

* MICRO PROCESSORS (P)

* DIGITAL SIGNAL CONTROLLERS (DSC)

* DIGITAL SIGNAL PROCESSORS (DSP)

* BUSSES (Data, Address, Input/output)

* SYSTEM CLOCK - Steps C / P Through Each Instruction

* READ ONLY MEMORY (ROM): Permanently Loaded With Instructions (FIRMWARE)

* RANDOM ACCESS MEMORY (RAM)

* STORES DATA IN PROCESSING / SHARES DATA WITH EXTERNAL PARTNERS

* REAL TIME CLOCK (RTC)

* COMMUNICATIONS CIRCUITRY - Ethernet Port, Printer Port, Communications Port (RS232c, RS485, RS422,

IEEE488)

EXAMPLES OF EMBEDDED SYSTEMS

Automatic Teller Machines or ATM's & Bank Vaults

Automotive & Automobile Engine Management systems: Electronic Dashboards, ABS brakes, transmission


4/9

controls.

Blue Tooth enabled Network Synchronization Applications

Control Systems (Manufacturing, Cryogenics, Electric Power)

Controls for Digital Equipment: CD Players, TV Remote, Programmable Sprinklers, Household Appliances, etc.

Computer motherboards (BIOS chips, RTCs)

Global Positioning and Navigation Systems

Household Appliances

Medical instruments controls - CT scanners, MRI Scanners, ECG, Pacemakers and implanted pumps, implanted

heart monitors, etc.

Supervisory Control and Data Acquisition (SCADA) systems

Telecommunications (Private Branch Exchanges, Custom Premises Equipment)

EMBEDDED - DESIGN METHODOLOGIES

* A procedure for designing a system

* Understanding your methodology helpsyou ensure you didnt skip anything.

* Compilers, software engineering tools, computer-aided design (CAD) tools, etc., can be used to:

help automate methodology steps;

keep track of the methodology itself.

EMBEDDED DESIGN GOALS

Performance. Overall speed, deadlines. Functionality and user interface. Manufacturing cost. Power consumption. Other requirements (physical size, etc.)

TYPICAL EMBEDDED SYSTEM HARDWARE

COMMERCIAL OFF-THE-SHELF COMPONENTS (COTS)e.g. wireless radios, sensors, I/O devices, Cheap

APPLICATION-SPECIFIC ICS (ASICS)ICs tailored to meet application needs, Good performance for their intended task(s), Original Ess were ASICs only

DOMAIN-SPECIFIC PROCESSORS DSPs Microcontrollers Digital Signal Controllers Microprocessors

EMBEDDED SYSTEMS - EARLY HISTORY

Late 1940s: MIT Whirlwind computer was designed for real-time operations. Originally designed to control an aircraft simulator. First microprocessor was Intel 4004 in early 1970s. HP-35 calculator used several chips to implement a microprocessor in 1972. Automobiles used microprocessor -based engine controllers starting in 1970s. Control fuel/air mixture, engine timing, etc. Multiple modes of operation: warm-up, cruise, hill climbing, etc. Provides lower emissions, better fuel efficiency.


5/9

EMBEDDED SYSTEMS

* MICROCONTROLLERS

Microcontroller is a highly integrated chip that contains all the components comprising a controller.

Typically, this includes a CPU, RAM, some form of ROM, I/O ports, and timers. A Microcontroller is designed

for a very specific task to control a particular system.

As a result, the parts can be simplified and reduced, which cuts down on production costs

Atmel, Microchip PIC, Maxim, Motorola

* DIGITAL SIGNAL CONTROLLERS

The Digital Signal Controller (DSC) is a powerful 16-bit (data) modified Harvard RISC machine that combines

the control advantages of a high performance 16-bit Microcontroller (MCU) with the high computation speed of a

fully implemented digital signal processor (DSP) to produce a tightly coupled single-chip single-instruction stream

solution for embedded systems design.

Microchip dsPIC, Texas Instruments

* DSP & RTOS


6/9

Specialized digital microprocessor used to efficiently and rapidly perform calculations on digitized signals that

were originally analog in form (eg voice)

The big advantage of DSP lies in the programmability of the processor, allowing parameters to be easily changed

Analog Devices, Texas Instruments

* VLSI

Very large-scale integration, the process of placing thousands (or hundreds of thousands) of electronic

components on a single chip.

Nearly all modern chips employ VLSI architectures, or ULSI (ultra large scale integration)

Altera, Cypress, Cirrus Logic, Xilinx

TYPES OF MICRO CONTROLLER

More than 140 Types of Micro Controllers AvailableSome of the examples are ..,

Microchip PIC, dsPIC, rfPIC Atmel AVR, ARM, 89cxx Analog Devices Texas Instruments ST Microcontrollers Zilog, Cypress, Maxim, Dallas, Motorola, etc.,

EMBEDDED SYSTEMS IN TODAYS WORLD

SIGNAL PROCESSING SYSTEMS - Real-Time Video, Set-top Boxes, DVD Players, Medical Equipment, Residential

Gateways

DISTRIBUTED CONTROL - Network Routers, Switches, Firewalls, Mass Transit Systems, Elevators

SMALL SYSTEMS - Mobile Phones, Pagers, Home Appliances, Toys, Smart Cards, MP3 players, PDAs, Digital

Cameras, Sensors, Smart Badges


7/9

BENEFITS OF EMBEDDED CONTROL DESIGN

Eliminates necessity of complex circuitry

Smarter products

Smaller size

Lower cost

User friendly

State of the art technology

FUTURE OF EMBEDDED CONTROL

Intelligent products are used everyday - Mobile Phones, Printers, Washing Machines, Microwave Ovens, Water

Purifier, Air Conditioners etc.

New generation Embedded Control will include Internet connectivity, RF controls & Blue Tooth.

THE JOB OPPORTUNITIES IN THE AREAS OF EMBEDDED CONTROL

Hardware Design Engineer

Software Design Engineer

Device Driver Developer

Kernel Developer

Network Engineer

RTOS Programmer

Software Engineer in Research & Development

COMPANIES ARE WORKING ON EMBEDDED SYSTEMS AND APPLICATIONS

AXES technologies

CG Smith

Converge Labs

Future Software

IBM

LUCENT

MASCON Sundaram Telematics

Visteon

WIPRO

TCS

Infosys

Robert Bosch


8/9

Kshema Technologies

and so on

NEW TRENDS IN EMBEDDED SYSTEM H/W

Systems-on-chip Usual (or desired) specs:

32-bit RISC CPU

Built-in interfaces to RAM and ROM

Built-in DMA, interrupt and timing controllers

Built-in interfaces to disk or flash memory

Built-in Ethernet/802.11 interfaces

Built-in LCD/CRT interfaces New SOCs appearing almost every week!

Examples Intel StrongARM SA-1110, Motorola PowerPC MPC823e NEC VR4181 Many, many more

EMBEDDED SOFTWARE PROPERTIES

Timeliness

Concurrency

Liveness

Interfaces

Heterogeneity

Reactivity

TIMELINESS

Time: systematically removed from theories of computation RTOSes often reduce the characterization of a task to a single number (its priority)

But: computation does take time

However, even with infinitely fast computers, time would still have to be dealt with

Physical processes evolve over time

Need to find abstractions that regain control of time!

CONCURRENCY

In the physical world, multiple things happen at once

Challenge: reconcile sequentially of software with the concurrency of the real world Classic approaches (semaphores, monitors etc) provide good foundation

But: potentially insufficient

One approach: compile concurrency away (Estrel)

Estrel: synchronous/reactive language

FSM based, deterministic behavior

Pros: Higly reliable programs

Cons: Too static for some systems


9/9

Middle ground is needed

LIVENESS

Programs must not terminate

Unlike the traditional Turing model of computation, halting is undesirableDeadlock is an absolute no- no

Correctness isnt just about getting the right final answer

Must consider things like timing, power consumption, fault recovery, security and robustness

REACTIVITY

Interactive systems:

react at their own speed (or the speed of the controlling human)

Transformational systems

Transform a data input to a data output (e.g. matrix multiplication)

Reactive systems

react continuously with environment, at the same speed

Must adapt to changing conditions

Resources and demands may change frequently

Real-time constraints

Safety-critical

Fault-tolerance can be a major issue

Documents

An Embedded System is a Special