3. System
A system is a way of working, organizing or
doing one or many tasks according to a fixed
plan, program or set of rules.
A system is also an arrangement in which all
its units assemble and work together
according to the plan or program.
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4. 4
SYSTEM EXAMPLES
WATCH
It is a time display SYSTEM
Parts: Hardware, Needles, Battery, Dial,
Chassis and Strap
Rules
1.All needles move clockwise only
2.A thin needle rotates every second
3.A long needle rotates every minute
4.A short needle rotates every hour
5.All needles return to the original position after 12 hours
5. 5
WASHING MACHINE
It is an automatic clothes washing SYSTEM
Parts: Status display panel, Switches & Dials, Motor, Power
supply & control unit, Inner water level sensor and solenoid valve.
Rules
1.Wash by spinning
2.Rinse
3.Drying
4.Wash over by blinking
5.Each step display the process stage
6.In case interruption, execute only the remaining
6. 6
EMBEDDED SYSTEM
Definition: An Embedded System is one that has computer
hardware with software embedded in it as one of its important
components.
SOFTWAREPROGRAM
#include <16f876a.h>
#use delay (clock=20000000)
#byte PORTB=6
main()
{
set_tris_b(0);
portb=255; //decimal
delay_ms(1000);
portb=0x55; //hexadecimal
delay_ms(1000);
portb=0b10101010; //binary
delay_ms(500);
}
Its software embeds in
ROM (Read Only
Memory). It does not
need secondary
memories as in a
computer
HARDWARE
7. Processor
A Processor is the heart of the Embedded System.
An embedded processor is a microprocessor that is used in
an embedded system.
For an embedded system designer knowledge of
microprocessor and microcontroller is a must.
Two Essential Units: Operations
Control Unit (CU), Fetch
Execution Unit (EU) Execute
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8. Monday,
April 29,
2024
Internal Architecture of 8086
8
Microprocessor Microcontroller
CPU is stand alone, RAM,ROM, I/O & timer
are separate.
CPU, RAM,ROM, I/O & timer all are on single
chip.
Designer can decide amount of RAM,ROM,
& I/O ports.
Fixed amount of on-chip RAM,ROM, & I/O
ports.
High processing power Low processing power
High power consumption Low power consumption
Typically 32/64 bit 8/16 bit
General purpose Single purpose(control oriented)
Less reliable Highly reliable
Eg.- 8086,8085 8051
13. Components of Embedded System
It has Hardware
Processor, Timers, Interrupt controller, I/O Devices, Memories, Ports,
etc.
It has main Application Software
Which may perform concurrently the series of tasks or multiple tasks.
It has Real Time Operating System (RTOS)
RTOS defines the way the system work. Which supervise the
application software. It sets the rules during the execution of the
application program. A small scale embedded system may not need an
RTOS.
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16. Features of an embedded
system
Single-functioned
Executes a single program, repeatedly
Tightly-constrained
Low cost, low power, small, fast, etc.
Life threatening
24/7/365
Reactive and real-time
Continually reacts to changes in the system’ s
environment
Must compute certain results in real-time without delay
17. Future of Embedded
processors
Embedded processor account for 100% worldwide
microprocessor production
Microprocessor production
Embedded:Desktop=100:1
Embedded processors in a house 40-50(approx)
Embedded processors in a modern car 50-60
18. Languages for Programming
Embedded Systems
Assembly language was the pioneer for
programming embedded systems till recently.
Nowadays there are many more languages to
program these systems. Some of the
languages are C, C++, Ada, Forth, and Java
together with its new enhancement J2ME.
The majority of software for embedded
systems is still done in C language.
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19. Recent survey indicates that approximately
45% of the embedded software is still being
done in C language.
C++ is also increasing its presence in
embedded systems. As C++ is based on C
language, thus providing programmer the
object oriented methodologies to reap the
benefits of such an approach.
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20. C is very close to assembly programming and
it allows very easy access to underlying
hardware.
A huge number of high quality compilers and
debugging tools are available for the C
language.
Though C++ is theoretically more efficient
than C, but some of its compilers have bugs
due to the huge size of the language.
These compilers may cause a buggy
execution.
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22. Real-time Systems
Embedded systems in which some specific
work has to be done in a specific time period
are called real-time systems.
Real time embedded systems are classified
into two types such as soft and hard real time
systems.
24. Stand Alone Embedded
Systems
Stand alone embedded systems do not require a host
system like a computer, it works by itself.
It takes the input from the input ports either analog or
digital and processes, calculates and converts the data
and gives the resulting data through the connected
device-Which either controls, drives and displays the
connected devices.
Examples:- mp3 players, digital cameras, video game
consoles, microwave ovens and temperature
measurement systems.
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25. Networked Embedded
Systems
These types of embedded systems are related to a
network to access the resources.
The connected network can be LAN, WAN or the internet.
Example:- home security system wherein all sensors are
connected and run on the protocol TCP/IP
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26. Mobile Embedded Systems
Mobile embedded systems are used in portable embedded
devices like cell phones, mobiles, digital cameras, mp3
players and personal digital assistants, etc.
The basic limitation of these devices is the other resources
and limitation of memory.
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27. Small Scale Embedded
System
Single 8 bit or 16bit Microcontroller.
Little hardware and software complexity.
They may even be battery operated.
Usually “ C” is used for developing these system.
The need to limit power dissipation when system is running
continuously.
Examples:- digital watches
Programming tools:
Editor, Assembler and Cross Assembler
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28. Medium Scale Embedded
System
Single or few 16 or 32 bit microcontrollers or
Digital Signal Processors (DSP) or Reduced
Instructions Set Computers (RISC).
Both hardware and software complexity.
Examples:- Ipod’ s
Programming tools:
C, C++, java, RTOS, Source code
Engineering Tool, Simulator, Debugger and
Integrated Development Environment (IDE).
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29. Sophisticated Embedded
System
It uses more than 32 bit microcontroller.
Enormous hardware and software complexity
Which may need scalable processor or configurable processor and
programming logic arrays.
Constrained by the processing speed available in their hardware
units.
Examples:-washing machine
Programming Tools:
For these systems may not be readily available at a
reasonable cost or may not be available at all. A compiler or
retargetable compiler might have to br developed for this.
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30. Embedded System
Constraints
An embedded system is software designed to keep in
view three constraints:
Available system memory
Available processor speed
The need to limit the power dissipation
When running the system continuously in cycles of
wait for events, run, stop and wakeup.
31. 31
• Household appliances:
Microwave ovens, Television, DVD
Players & Recorders
• Audio players
• Integrated systems in aircrafts and
missiles
• Cellular telephones
• Electric and Electronic Motor
controllers
• Engine controllers in automobiles
• Calculators
• Medical equipments
• Videogames
• Digital musical instruments, etc.
Applications
