The Past Present and The Future
An embedded system is a computer system with a
dedicated function within a larger mechanical or
electrical system, often with real-time computing
constraints. It is embedded as part of a complete
device often including hardware and mechanical parts.
A simpler definition: A small remote controlled toy,
electronic control units in automobiles, aircraft and
Even simpler: Anything which does not have a desktop
computer or a laptop computer and used for a specific
purpose and does contain a microcontroller
Real Time System
Does it mean a Really Fast System?
Does it mean that the correctness is a function of
Mathematically Correctness = f(time)
Is too early bad and too late also bad?
Are missed dead lines sometimes not acceptable
where as its ok some other times?
Everything in the world is a real time system where in
some cases time t ∞
So what is a real time system
A real time system reacts to a given stimulus within a
fixed time interval
Too early is too bad and too late is also too bad.
Its better not to do it rather than doing it late.
Example if a missile is launched 10 seconds late, it will
miss the target by 30km. Just to appreciate the missile,
it takes a parabolic trajectory and follows the laws of
Soft Real time system v/s Hard Real
In a hard real time system, a delay in response can be
really catastrophic and timing is very critical.
On the other hand a soft real time is quite soft on time.
Why embedded systems
A computer has a processor which is
general purpose. A processor can be used
to run a specific operating system which
in turn can host a set of services
A processor is used in cases where we
want to do something general and
generic. On the other hand a controller is
used for a specific application like
controlling the motion of a toy car.
Imagine a toy car that has a huge
computer connected to it to control its
motion! Will any one buy it?
Evolution of embedded systemsYear 1833: Michael Faraday describes the "extraordinary case" of his
discovery of electrical conduction increasing with temperature in
silver sulphide crystals
Year 1874: In the first written description of a semiconductor diode,
Ferdinand Braun notes that current flows freely in only one direction
at the contact between a metal point and a galena crystal.
Year 1959: Robert Noyce builds on Jean Hoerni's planar process to
patent a monolithic integrated circuit structure that can be
manufactured in high volume.
Year 1974: First general purpose Microprocessor family is announced. It
was introduced by a company called Integrated Electronics for a Japanese
customer called Busicon. The Japanese customer declined to purchase the
chipsets manufactured by Intel. This was later sold by Intel as the first 4
bit processor (Intel 4004)
Challenges in Embedded Design
In the past most of the systems were driven by
mechanical valves or discrete electronics
A humble tape recorder which can play for 40 minutes has
been replaced by a tiny MP3 player which can play
continuously for 12 to 14 hours
Becoming slaves to software
With evolution, the processors are getting cheaper . Many
vendors are providing board support packages and cross
Free code is available all over the web
Features are increasing day by day.
A mobile phone has changed from a simple connectivity device
to a Make Up Kit
A space mission now has an operating system running and a load
of application programs
Recently a plastic part was printed in space by sending the
drawings to the NASA space station
Heart valves are printed using 3D printers due to non availability
of cadaver donors
Extremely complex code base leads
1. Mariner Bugs Out (1962)
Cost: $18.5 million
Disaster: The Mariner 1 rocket with a space probe headed for Venus diverted
from its intended flight path shortly after launch. Mission Control destroyed the
rocket 293 seconds after lift-off.
2. World War III… Almost (1983)
Cost: Nearly all of humanity
Disaster: The Soviet early warning system falsely indicated the United States had
launched five ballistic missiles. Fortunately the Soviet duty officer had a “funny
feeling in my gut” and reasoned if the U.S. was really attacking they would launch
more than five missiles, so he reported the apparent attack as a false alarm.
Cause: A bug in the Soviet software failed to filter out false missile detections
caused by sunlight reflecting off cloud-tops.
Setting the date to 1-Jan-1970 bricks your iPhone
AT&T Lines Go Dead (1990)
Cost: 75 million phone calls missed, 200 thousand airline reservations lost
Disaster: A single switch at one of AT&T’s 114 switching centres suffered a minor mechanical
problem and shut down the centre. When the centre came back up, it sent a message to other
switching centres, which in turn caused them to shut down and brought down the entire AT&T
network for 9 hours.
Cause: A single line of buggy code in a complex software upgrade implemented to speed up calling
caused a ripple effect that shut down the network.
Ariane Rocket Goes Boom (1996)
Cost: $500 million
Disaster: Ariane 5, Europe’s newest unmanned rocket, was intentionally destroyed seconds after
launch on its maiden flight. Also destroyed was its cargo of four scientific satellites to study how the
Earth’s magnetic field interacts with solar winds.
Cause: Shutdown occurred when the guidance computer tried to convert the sideways rocket velocity
from 64-bits to a 16-bit format. The number was too big, and an overflow error resulted. When the
guidance system shut down, control passed to an identical redundant unit, which also failed because
it was running the same algorithm
Need of the hour
Development practices : Embedded software systems
poses an extraordinary challenge to the software
engineers due to their complexity functionality
represented by states and events; real-time behaviour
of events and expected actions; combined
software/hardware systems equipped with distributed
software, computers, sensors, and actuators; high
demands on availability, safety, information security,
and interoperability; and long-lived systems in which
embedded software is expected to work reliably.
The Evolution of programming
Predominantly around 70-80% people use ‘C’ as a
preferred programming language for embedded
OOP like ‘C++’ and ‘JAVA’ are becoming a new
trend in terms of model based design, for example
Design inspection and verification
With increasing complexity, verification and
validation are playing a major role in embedded
Many players are venturing into this new market
Evolution of Orthogonal defect classification
New challenge Cyber Era
Most of the devices are now capable of
The security requirements for a huge base of
connected devices are distinct on account of low
memory foot print, low power consumption,
constrained middleware etc.
Embedded security is a new differentiator for
Cyber attacks and its threats
Embedded security is a new differentiated skill in
Embedded Encryption: Standard symmetric key
encryption algorithms like AES , public private key
pair using RSA encryption
The Internet of Things is a new thing happening in
What is it after all?
In simple terms it is a connection of edge devices to
The Internet of Things (IoT) is the network of
physical objects—devices, vehicles, buildings and
other items—embedded with electronics, software,
sensors, and network connectivity that enables these
objects to collect and exchange data.
About the author
Srikanth KS completed his MS from BITS Pilani
specialized in software systems .He works in a multi
national company as a software engineer responsible for
design and development of embedded software.
He has been in this industry since 15 years.
He has been a part of the journey by working with 8051
microcontrollers and is currently working on 32 bit
He has a passion to teach engineering students and to
provide them the knowledge that they seldom get in their
All his posts can be found at
The Author thanks Hari KA for providing a platform
http://www.primedin.in/ which can be used for
presenting online lectures
The Author would like to thank all authors who have
contributed directly or indirectly in the preparation of
this slide show.
All information has been taken from the public
domain and the author thanks all of them for
providing the information.