Embedded Systems

• Normal everyday items contain computer chips, complete with CPU, memory, programs– Television, Entt. Center, Automobiles, Irrigation, – MP3, cell phones, GPS, – microwave, home alarms, thermostats, – network routers, game consoles

• Special purpose machines contain computers– Manufacturing, metering, sensing, – ATM machines, kiosks– Medical Instruments, Aircraft, Satellites,

Need to know: HardwareSoftware

IMPACT

• $45 billion market in 2004, rising to $88 billion in 2009• Many more embedded processors per person, than

general purpose processors– A cell phone may have 20-100 separate processors– Value of embedded electronics in Automobiles: 25% of total cost,

to rise to 35% by 2015– Embedded market is 50 times the desktop market

• Application Domains:– Automotive, Avionics, Industrial Automation, Telecommunication,

Consumer Electronics, Medical, IT hardware

• Cutting edge:– Multicore processors, Network on Chip, System on chip (e.g. the

iPhone, PS-3)

Embedded Systems

• A “special purpose” unit– e.g. simple cell phone (it does not run MS-Word)

• Has a CPU, memory and programs that control mainly physical things– The program is preinstalled and cannot be changed

easily

• Has limited processing power and limited electrical power and limited data storage

• Has “intelligence”– Can be configured, personalized, “programmed”

Need to know: Computer Architecture

Schematic

CPU

Memory

Permanent Memory

Input device (keyboard)

Sensorsto measure

physical values

Actuatorsto

controlphysicalthings

Outputdevice (screen)

bus

program

Need to know: Digital Logic, Electrical Circuits, Computer Architecture

The Seven Segment Display

Display ControllerCounter

Clock

00000001001000110100…..

DSL Router

5. JTAG (Joint Test Action Group) test and programming port. 6. RAM, a single ESMT M12L64164A 8 MB chip.7. Flash memory, obscured by sticker. 8. Power supply regulator.9. Main power supply fuse.10. Power connector.11. Reset button.12. Quartz crystal.13. Ethernet port.14. Ethernet transformer, Delta LF8505.15. KS8721B Ethernet PHY transmitter receiver.16. USB port.17. Telephone (RJ11) port.18. Telephone connector fuses.

Netgear DG632 ADSL Modem/router. 1. Telephone decoupling electronics (for ADSL).2. Multicolor LED (displaying network status).3. Single color LED (displaying USB status). 4. Main processor, a TNETD7300GDU, a member of Texas Instruments' AR7 product line.

MP3 player

• Large “flash” memory to store songs– Songs (audio) stored in digital form, then compressed

to a set of numbers that are of the “MP3” format

• CPU runs program in main memory– Decompresses audio and generates “raw digital

audio”– Gets user input from button– Displays information on screen

• Digital-Analog converter generates audible sound waves and sends to speaker/headphones

Need to know: Software Algorithms, Device Drivers and programming

GPS Navigator

• Complex system with many components– GPS Radio– GPS signal processor– Map database– Processor to control display and compute routes,

locations, points of interest– Video image processor to control actual screen

• May contain several different CPUs in one package

GPS Radio• Receives data from several

satellites, converts RF to digital signals– Separate for each satellite

Radio receiver circuitry

Signals (digital) from each satelliteon separatewires

A set of at least 24 Medium Earth Orbit satellites that transmit precise microwave signals,

A GPS receiver can determine its location, speed, direction, and time.

GPS signal processor

• Correlates satellite signals– Computes timing differences– “triangulates” location

GPS dataprocessor

Current location in latitude and longitude

Need to know: Radio, Signal processing, Algorithms

GPS Navigator

• The user interface – show location on map and provide useful other information

GPS ComputerDisplay

Processor

MAP database

Touch Sensor

Need to know: Computer Graphics, Graph Theory

Cell Phone (basic)

• Multi-channel Radio (transmit and receive)• Digital processor for CDMA or TDMA processing

– GSM is TDMA – each person communicates in a pre-assigned slice of time on channel

– CDMA is a complex code modulation method

• Encryption/Decryption hardware• Channel and tower hopping• Transmit power control• Analog to digital to RF conversions• Display, phone book and other electronic

functionsNeed to know: Radio Modulation, Digital Signal Processing

Automobile Computers

• Engine control computer • Advanced diagnostics • Simplification of the manufacture and design of

cars • Reduction of the amount of wiring in cars • New safety features • New comfort and convenience features

Need to know: Control Systems, Electrical Circuits, Real Time Control

Engine Control Computer (ECU)

• Read sensors (temp, pedal position, exhaust) and control fuel injector timing and spark timing

• Control engine fan and other actuators• Handle the CAN (communication area

networking) that is becoming common in cars.

• Interface with climate and other passenger controls

• Provide diagnostics

Need to know: Real Time Operating Systems

Other computers in car

• There are more processors in the car other than ECU– ABS system– Climate control– Cruise control– Radio– Dashboard– Automatic doors, lights and such

• Cars also have networks for “simplified wiring” as well as automotive control networks.

Simplified Wiring

OLD NEW

Many connecting wires

One wire runs all over the vehicle and carries power and signal

SWITCHES

LAMPS

Switches + signal encoders

Lamps + signal decoders

Automobile Networking

• As multiple computing units get into cars, a networking standard is being used– CAN 2.0 is predominant

• Functions– Communicate between subsystems– Reduce wires– Multiplexing standard– Network addressing– “multiple networks”

coming in the future

Need to know: Computer Networking

Embedded Systems

• There are more “embedded systems” in the world than regular computers

• Explosive growth• Research directions:

– Power management– “system on a chip”– “network on a chip”– Low resource but high impact computing– Intelligent coupling of small wireless devices– MORE