This document defines and compares embedded systems and computer systems. It discusses the categories and requirements of embedded systems, including standalone, real-time, and networked systems. It describes the typical hardware architecture of embedded systems, including processors, memory, input/output components, and communication devices. The document outlines advantages like low cost and small size, and disadvantages such as difficulty in maintenance. It provides examples of applications for embedded systems in various industries.
2. CONTENTS
DEFINITION
COMPUTER SYSTEM vs EMBEDDED SYSTEM
CATEGORIES AND REQUIREMENTS OF EMBEDDED SYSTEMS
DESIGN AND ARCHITECTURE OF EMBEDDED SYSTEM
ADVANATAGES AND DISADVATAGES
APPLICATIONS AND CONCLUSION
3. Like any other computing system, an embedded system is a combination of hardware and
software which is custom built for system specific purpose, as the requirements of each system
vary considerably.
5. COMPUTER EMBEDDED
SYSTEM STSTEM
• General Purpose: these are the
computers we use them for
performing a variety of everyday
tasks such as playing games, word
processing, scientific calculations,
etc.,
• These are sets of systems which have
a CPU and other peripherals, input
output devices, monitoring devices
assembled with them.
• Specific Purpose: these perform
single well defined task which is
custom built for system specific
purposes such as process control,
automation,
aeronautics, aviation etc.,
• Is a custom built collection of on
board chips which are put together to
provide a functional specific output.
6. COMPUTER EMBEDDED
SYSTEM STSTEM
• They are very cumbersome
machines such as work stations
and mainframe computers.
• They are not time critical in their
operations.
• These are hand held devices which
are customized and have eased
mobility.
• In many of the case they have to
be very time critical responding to
various real time interrupts.
8. CATEGORIES OF EMBEDDED
SYSTEMS
CATEGORIES
• Stand-alone embedded systems:
which works in a stand-alone
mode: taking inputs and giving
outputs. Such systems are required
in process control, modern
entertainment equipment's ,
automations.
EXAMPLES
9. CATEGORIES OF EMBEDDED
SYSTEMS
• Real Time embedded Systems:
Sometimes embedded systems are
required to carry out specific tasks
in a specified amount of time.
They can be hard real time (real
time constrains has to be strictly
maintained) Or Soft Real time
(Real time constrains are not so
critical).
10. CATEGORIES OF EMBEDDED
SYSTEMS
• Networked Applications:
Embedded systems which are need
to be connected in a networked
environment. Typically one based
on TCP/IP or web servers
(HTTP).
11. CATEGORIES OF EMBEDDED
SYSTEMS
• Wireless networks that can support
high speeds, mobile devices are
capable of supporting high data
rates, with voice and internet. The
special requirements of these devices
is threefold: they should have
powerful computing and
communication capabilities, they
should be capable to perform some
real time tasks, in addition to non
real-time tasks.
13. HARDWARE ARCHITECTURE OF
EMBEDDED SYSTEMS
• An embedded system is built around a processor.
• The central processing unit does the necessary computation based on the input
it receives from various external devices.
• The functionality of the CPU is an embedded system is same as the functionality of the
CPU in a desktop, except that the CPU in an embedded system is less powerful.
• The processor has limited internal memory, and if this internal memory is not sufficient
for a given application external memory devices are used.
• The hardware also includes any components that facilitates the user-application
interaction, such as display units, keypads etc.
20. 3.LATCHES AND BUFFERS:
• Processor based systems need to derive external devices such as LEDs,
displays, relays, etc.
• The processor does not directly interface with these devices.
• Flip-flop logic chips are used to drive external drivers.
• These chips hold the processor output data to be send to the external devices.
4.CRYSTAL:
• The CPU needs a clock source, and a crystal oscillator generates the clock.
• The Crystal is choose based on the clock frequency of the processor.
• Micro-controllers provide an on chip oscillator and you connect an external
crystal or ceramic resonator.
• The clock generation circuitry determines the various states of machine cycles.
21. 5.RESET CIRCUIT:
• It is generally built in the hardware to take care of any unforeseen problems.
• This circuit handles software handles software hang-ups, power supply failures, etc.
• The processor sends a status signal to this circuit periodically.
• If in case this signal is not received, it is an indicator that some thing is wrong,
which is then reset by this circuit.
• Single chip solutions are also available.
6.KEYPAD:
• Each embedded systems offer different capabilities for providing user input.
• Handheld computers are provided with either full-fledged QWERTY keyboard or a
form of handwriting recognition.
• Depending on the needs they can vary from few keys to a full-fledged keyboard.
25. 9.COMMUNICATION DEVICES:
• Embedded Systems need to interface with the external devices, thus they need
communication interfaces.
• Most processors provide a serial interface to send and receive data in serial form.
Networked embedded systems are provided with Ethernet interface.
• Mobile phones and handheld computers are provided with a number of
communication interfaces as such as serial, parallel, infrared, Bluetooth, and
USB(Universal Serial Bus).
10.PROGRAMMABLE LOGIC DEVICES:
• The manifold requirements are met using PLDs(Programmable Logic Devices).
Using design automation tools such as Verilog and VHDL.
• This Single chip can be Programmable Logic Device (PLD), Field Programmable
Gate Array, Programmable Array Logic (PAL).
• Major Suppliers are Axel, Adaptive Silicon, Altera, Atmel, Cypress
Semiconductors, Quick Logic, Transcend and Xilinx.
27. ADVANTAGES OF EMBEDDED SYSTEMS
Low cost.
Small size.
High reliability.
Fast operations.
Easy to manufacture.
Fewer interconnections.
DISADVANTAGES OF EMBEDDED SYSTEMS
Hard to maintain.
Doesn’t evolve with technology improvement.
Hard to carry files from one machine to other.
Hard to backup embedded files.
33. CONCLUSION:
• Now a days its implementation is faster.
• Its development is necessary to our future.
• These type of systems emerges a new
revolution in communication and digital
signal processing.
• It is cheap and best.