2. TOPICS TO BE DISCUSSED
• System
• Embedded System
• Components
• Classifications
• Processors
• Applications
3. INTRODUCTION TO EMBEDDED
TECHNOLOGY
The embedded system is a combination of computer
hardware, software additional electrical & mechanical
parts
A computer is used in such devices primarily as a means
to simplify the system design and to provide flexibility.
Embedded systems employ the use of a RTOS (Real-
Time Operating System).
4. WHAT IS AN EMBEDDED SYSTEM?
Any device that includes a programmable computer but
is not itself a general purpose computer is called as
embedded system . So embedded system are design to
work for a specific task
In an embedded system the hardware and operating
system are tightly coupled with each other so you can‟t
distinguish between the two.
Common examples of embedded systems include MP3
players, navigation systems on aircraft and intruder
alarm systems, etc.
5. WHY STUDY EMBEDDED SYSTEMS?
Embedded systems are playing important roles in
our lives every day, even though they might not
necessarily be visible. Some of the embedded
systems we use every day control the menu system
on television, the timer in a microwave oven, a cell
phone, an MP3 player.
6. TYPICAL EMBEDDED SYSTEM CONTAINS:
INPUT
SYSTEM • Display screen
• Mobile • Any kind of
• T.V. • Sensors
physical change
• Control knobs
DEVICE OUTPUT
SYSTEM
• Microprocessor MEMORY
• Microcontroller
• RAM
• Digital Signal • ROM
Processor
• Stick Memory
PROCESSORS
7. CLASSIFICATION OF EMBEDDED SYSTEM:
Non –reactive embedded
1.Reactive embedded system
system
It changes according to
It never changes according to
environment.
any kind of change.
Ex: Night & day vision image.
Ex: Washing machine
2. Single function embedded
Multi function embedded system
system
It can execute multiple types of
It executes same program
related job.
repeatedly.
Ex : Smartphone
Ex :ECG machine.
3. Real time embedded system
Non real time embedded system
It works within a timeframe
It has no time constraint
Ex: rapid opening and closing
of shutter.
8. SOME IMPORTANT POINTS WHILE
DEVELOPING AN EMBEDDED SYSTEM
ARE AS FOLLOWS:
Cost
Size
Power consumption
Memory requirement
Development time
Reliability
9. Processors used in Embedded Systems
Digital Signal
Microprocessors Microcontrollers Processors
(DSP)
10. MICROCONTROLLERS
All the small embedded system has
Microcontrollers instead of Microprocessors. It is
used where there nothing is to be processed and
inspite of that it controls the execution.
11. WHY MICROCONTROLLERS?
A microcontroller is a single silicon chip with
memory and all Input/Output peripherals on it.
Hence a microcontroller is also popularly known as
a single chip computer. Normally, a single
microcomputer has the following features :
o Arithmetic and logic unit
o Memory for storing program
o EEPROM for nonvolatile data storage
o RAM for storing variables and special function
registers
o Input/output ports
12. o Timers and counters
o Analog to digital converter
o Circuits for reset, power up, serial programming,
debugging
o Instruction decoder and a timing and control unit
o Serial communication port
13. MEMORY ARCHITECTURE OF
MICROCONTROLLER
Princeston Model Harvard Model
Processor Controller
Memory data and Program
Data memory
program memory
Used in Embedded
Used in PC‟s. systems.
Data and program are It allows parallel path
fetched together. for both data and
instructions.
14. REGISTERS
All the Microcontrollers has internal memory called
as registers, named as R0, R1, R2, R3……..
In case of AVR, we can have 32 such general
purpose registers.
But there are many other types of registers also
such as i/p – o/p register etc.
Registers are fast than RAM. So, for calculations
ALU always uses registers.
Registers are limited in nos., so data is stored and
retrieved from memory. This is called as Load store
Architecture or Reg.-Reg. Architecture.
15. BUSES
Buses are the communication media which sends
and receive signals, and is used to connect all
internal components of Microcontroller.
Buses has three types of lines, according to which
buses are of three types:-
Data BUS
Address BUS
Control BUS
17. WHY AVR MICROCONTROLLERS ?
It is a microcontroller created by ATMEL company.
It gives freedom to be programmed in various
languages.
ATMEL has a large range of M.C., from the 6pined
tiny series to the 100pined mega series.(in various
different families)
High performance
Low power consumption
Integrated EEPROM and SRAM.
Atmel AVR 8-bit to 32-bit microcontrollers provides
great design flexibility to developers.
18. FEATURES OF EMBEDDED SYSTEM
Embedded systems do a very specific task, they
cannot be programmed to do different things.
Embedded systems have very limited resources,
particularly the memory. Generally, they do not
have secondary storage devices such as the
CDROM or the floppy disk.
Embedded systems have to work against some
deadlines. A specific job has to be completed
within a specific time. In some embedded systems,
called real-time systems, the deadlines are
stringent. Missing a dead line may cause a
catastrophe – loss of life or damage to property.
19. Embedded systems are constrained for power, As
many embedded systems operate through a
battery, the power consumption has to be very low.
Embedded systems need to be highly reliable.
Once in a while, pressing ALT-CTRL-DEL is OK on
your desktop, but you cannot afford to reset your
embedded system.
Some embedded systems have to operate in
extreme environmental conditions such as very
high temperatures and humidity.
21. PROGRAMMING MODEL
Char st[ ] =
“HELLO”;
main( )
{--------------;
--------------; Statements
}
Compile (data + machine instruction)
Stored in specified memory(FLASH MEMORY)
Execution only data is copied to RAM
22. IMPORTANT POINTS
Embedded system don‟t have hard disk instead of
that have a memory called as Flash memory.
So, in all Embedded system program is stored in
Flash memory and the data is executed in RAM.
Flash is some what like Read Only Memory(ROM)
in this we can write the data once but we cannot
modify it again and again so it is copied to RAM for
execution.
Once a program is executed the RAM discard the
copy of data.
23. STEPS TO CREATE A PROGRAM
Create the program in “PROGRAMMABLE
NOTEPAD”.
Open the „CYGWIN‟ shell. It is the command prompt
to execute embedded system programs.
Build
Burn
24. DESIGN OF AN EMBEDDED SYSTEM – A CASE
STUDY
To understand the design of a simple embedded
system let us first consider the idea of a data
system. The data acquisition system is shown in
the next slide.
25. For example let me consider a simple case of
temperature measurement embedded system.
o First we must select a temperature sensor like
thermistor or AD590 or LM35 or LM335 or LM75
etc.
o After this the analog data is converted into digital
data and at the same time proper signal
conditioning is done.
o This digital input is fed to the microcontroller
through its ports.
o By developing a suitable program (Embedded C or
Assembly) the data is processed and controlled.
o For this purpose keil or Ride or IAR ARM
Embedded workbench C compilers can be used.
26. o Once the program is debugged, and found error
free it can be dumped into the microcontroller flash
memory using ISP (Philips - Flash magic or any
ISP).
o Now, your microcontroller chip acts as an
embedded chip.