For Students & whose Interested In Embedded Systems & Embedded Technology Starting Topics of "What is embedded System and its Applications And Embedded Systems Introduction & Differentness Types of Embedded Operating Systems.
EMBEDDED SYSTEMS INTRODUCTION
• Embedded Systems.
• Real time Systems.
• Operating Systems.
• An embedded system is combination of
computer hardware and software which is
dedicated to particular application or product.
Embedded system is embedded as a
subsystem in a larger system which may or
may not be a computer system.
“Embedded Systems are the electronics systems
that contain a microprocessor or a Mu,but we
do not think as computers-the computer is
hidden or embedded in the systems.”
Some Interesting Examples
of Embedded systems:
Has a Programmable
Speed Control ,Timer
Product: vendo vue
A robot hand
Product: NASA's Twin
20Mhz Power Pc.
Commercial Real-Time OS
Software and OS was
developed during Flight
To mars and
Downloaded using a
Microprocessor: Intel X86
Os:windows XP Embedded
Product: Dresser Wayne
Ovation iX Gas Pump.
Os: Windows CE
Display video ads & is
networked to gas station's
back office computer
systemes.also has remote
Product: Bernina Artista
200 Sewing Machine
Can Download New
images from the
internet and sew
• Single –functioned
-Executes a Signal Program ,Repeatedly
• Low Power
-Battery Power Devices
-Increases systems cost in wall powered devices
• Dedicated Systems
-Programmability rarely used
-Continually reacts to change in the system’s
What is a Real-Time Systems?
• A System is called real-time:
-whenever we need to quantitatively express in
order to describe its behavior.
- After temperature exceeds 500 degrees coolant
shower must start within 100m sec.
-Every real-time task is associated with some time
-Logical correctness of results and time at which
they are produced.
Types Of Real-Time Systems
• A tasks have deadlines associated with them.
• A classification based on consequence of a
-Hard real-time systems.
-Soft real-time systems.
-Firm real-time systems.
Hard Real-Time systems
• If a deadline is not met:
-The systems is said to have failed.
• Many hard real-time system are safety-critical
-Failure can cause severe damage(loss of life)
-No fail-safe state.
- Safety though increased reliability
-Atomic Reactor Control
Firm real-time systems
• It define is missed occasionally
-systems dose not fail
-result produced by task after deadline are rejected.
- “Late answer are wrong answer.”
-video played on computer.
Soft Real-time systems
• The usefulness of a result degrades after its deadline,
thereby degrading the system's quality of service.
• Soft real-time systems are typically used where there is
some issue of concurrent access and the need to keep
a number of connected systems up to date with
- software that maintains and updates the flight plans
for commercial airliners.
Introduction to Embedded System I/O Architectures
Other Classification of ES
• Small Scale Embedded Systems.
– Use single 8 bit or 16 bit microcontroller
– Little hardware and software complexity
– Embedded software IDE is specific to
– Software has to fit in given memory
– Power consumption is limited
Medium scale embedded system
– Single or few 16 bit, 32 bit microprocessor
– DSP or ARM is used
– Both hardware and software complexities
– C,C++, Visual C++, Java is popular for prog.
Large scale embedded system
– Enormous hardware and software complexities
– Several processors/controllers are used
– FPGA, DSP, DSC, IP core on VLSI chip, ASIC is
– Hardware software or operating systems codesign is required
– Some critical functions are implemented in the
hardware (instead of software) to achieve speed
– Development tools available are costly
– Needs team work for development
Operating Systems For Embedded
• Many of the components of the embedded
systems are integrated on to a single chip. This
concept is known as System on Chip (SOC)
Examples : 8051 projects, PIC uc based projects.
List of OS for Embedded Systems
iOS (a subset of Mac OS X)
– Maemo based on Debian deployed on Nokia's Nokia 770, N800 and N810 Internet Tablets.
– MeeGo merger of M
– oblin and Maemo
– webOS from Palm, Inc., later Hewlett-Packard via acquisition, and most recently at LG Electronics through
acquisition from Hewlett-Packard
– Ångström distribution
– Familiar Linux
Inferno (distributed OS originally from Bell Labs)
PEN/GEOS on HP OmniGo 100 and 120
Palm OS from Palm, Inc; now spun off as PalmSource
Windows CE, from Microsoft
– Pocket PC from Microsoft, a variant of Windows CE.
– Windows Mobile from Microsoft, a variant of Windows CE.
– Windows Phone from Microsoft,
DIP DOS on Atari Portfolio
MS-DOS on Poqet PC, HP 95LX, HP 100LX, HP 200LX, HP 1000CX, HP OmniGo 700LX
Newton OS on Apple Newton Messagepad
Plan 9 from Bell Labs
Why an OS at all?
• Same reasons why we need one for a
• Not all services are needed for any device.
Large variety of requirements and
•Critical applications with high functionality (medical application, space
•Critical applications with small functionality (ABS, pace marker…)
•Not very critical applications with varying functionality (PDA,Phone,Smart
microwave often, …)
Why is a desktop OS not suited?
• Monolithic kernel is too feature reach.
• Monolithic kernel is not modular, fault-tolerant,
configurable, modifiable, … .
• Takes too much space.
• Not power optimized.
• Not designed for mission-critical applications.
QNX 4 RIOS
• The QNX 4 RTOS is developed by QNX Software Systems Ltd.
for the applications in consumer electronics, telecommunications,
automotive systems, medical instrumentation which need high
superior performance, sophisticated functionality, and massive
• PlatformsIntel 8088, x86, MIPS, PowerPC, SH4,ARM, StrongARM, Xscale
• A number of design innovations were developed for QNX 4 RTOS
to deliver the full performance of the hardware.
• Linux has become popular on embedded devices—especially
consumer gadgets, telecom routers and switches, Internet
appliances and automotive applications.
• It is easy to slim down the operating environment by removing
utility programs, tools, and other system services that are not
needed in an embedded environment.
• It is more encouraging that the Linux code is widely available
portable to any processor.
• Linux doesn't require the user to pay license fees or royalties—
particularly important to developers of consumer
electronics, who have narrow margins.
• Windows CE is first introduced in the Handheld PC (H/PC) set of products
in November 1996.
• Microsoft Windows CE (now officially known as Windows Embedded
Compact and previously also known as Windows Embedded CE
• Several advantages for Windows CE includes a subset of the Win32, low
overhead device driver model and built-in power management.
• The application of Windows CE includes consumer electronics like
handheld PC, Auto PC, video game player and digital camera, and
industrial products like barcode reader and programmable logic
Programming language in embedded