Transcript embed-sys-v01 - Arizona State University

Embedded Systems
• Normal everyday items contain computer chips,
complete with CPU, memory, programs
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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:
Hardware
Software
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
Output
device
(screen)
Input device
(keyboard)
program
CPU
Memory
Sensors
to measure
physical
values
bus
Permanent Memory
Actuators
to
control
physical
things
Need to know:
Digital Logic, Electrical Circuits, Computer Architecture
The Seven Segment Display
Clock
Display
Controller
Counter
0000
0001
0010
0011
0100
…..
DSL Router
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.
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.
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
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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
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.
Signals
(digital)
from each
satellite
on separate
wires
GPS signal processor
• Correlates satellite signals
– Computes timing differences
– “triangulates” location
GPS data
processor
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 Computer
Display
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 preassigned slice of time on channel
– CDMA is a complex code modulation method
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Encryption/Decryption hardware
Channel and tower hopping
Transmit power control
Analog to digital to RF conversions
Display, phone book and other electronic
functions
Need 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
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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
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Many connecting
wires
Switches +
signal
encoders
One wire runs all
over the vehicle
and carries
power and
signal
Lamps +
signal
decoders
Automobile Networking
• As multiple computing units get into cars, a
networking standard is being used
– CAN 2.0 is predominant
• Functions
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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:
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Power management
“system on a chip”
“network on a chip”
Low resource but high impact computing
Intelligent coupling of small wireless devices
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