ch1_1_Introduction_To_Embedded_Systems.pptx.pdf

Computers as Components
3e
© 2012 Marilyn Wolf
What is an Embedded
System?

3e
3e

3e
3e
Examples
 Digital Printers
 Automobile: engine, brakes, dash, etc.
 Airplane: engine, flight controls, nav/comm.
 Household appliances (microwave, blenders etc)
 Samsung SmartThings
https://www.smartthings.com/
 RoboCV http://robocv.com/
 Microsoft HoloLens https://
www.microsoft.com/microsoft-hololens/en-us
 Google TiltBrush https://www.tiltbrush.com/
 https://
www.datamation.com/mobile-wireless/75-top-iot-devices-1.
html
 Holoportation:

3e
3e
What is an embedded
system?
Embedded computing system: any
device that includes a programmable
computer but is not itself a general-
purpose computer.

3e
3e
Embedding a computer
CPU
mem
input
output analog
analog
embedded
computer

3e
3e
Early history
 Late 1940’s: MIT Whirlwind computer
was designed for real-time
operations.
 Originally designed to control an aircraft
simulator.
 First microprocessor was Intel 4004
in early 1970’s.
 HP-35 calculator used several chips
to implement a microprocessor in
1972.

3e
3e
Early history, cont’d.
 Automobiles used microprocessor-
based engine controllers starting in
1980.
 Control fuel/air mixture, engine timing,
etc.
 Multiple modes of operation: warm-up,
cruise, hill climbing, etc.
 Provides lower emissions, better fuel
efficiency.

3e
3e
Automotive embedded
systems
 Today’s high-end automobile may
have 100 microprocessors:
 4-bit microcontroller checks seat belt;
 microcontrollers run dashboard devices;
 16/32-bit microprocessor controls
engine.
 Low-end cars use 20+
microprocessors.

3e
3e
 https://
cecas.clemson.edu/cvel/auto/systems/auto-systems02.html

3e
3e
BMW 850i brake and stability
control system
 Anti-lock brake system (ABS): pumps
brakes to reduce skidding.
 Automatic stability control (ASC+T):
controls engine to improve stability.
 ABS and ASC+T communicate.
 ABS was introduced first---needed to
interface to existing ABS module.

3e
3e
BMW 850i, cont’d.
brake
sensor
brake
sensor
brake
sensor
brake
sensor
ABS
hydraulic
pump

3e
3e
Discussion
 Describe a novel example of
embedded system that you have
encountered recently?
 What is not an embedded system?
Give examples?
 What do you think are the core skills
required for developing embedded
systems?

3e
Micro Processor
Vs
Micro Controller

3e
3e
Microprocessor
Microprocessor is an IC (integrated circuit)
which has only the CPU inside them i.e.
only the processing power. Examples are
Intel’s Pentium 1,2,3,4, core 2 duo, i3, i5
etc.
 The microprocessors don’t have RAM,
ROM, and other peripheral on the chip. A
system designer has to add them
externally to make them functional.
Application of microprocessor includes
Desktop PC’s, Laptops, notepads etc.

3e
3e
Microcontroller
 Microcontroller has a CPU, in
addition with a fixed amount of
RAM, ROM and other peripherals all
embedded on a single chip.
 At times it is also termed as a mini
computer or a computer on a
single chip.
 Today different manufacturers
produce microcontrollers with a
wide range of features available in
different versions. Some
manufacturers are ATMEL,
Microchip, TI, Freescale, Philips,

3e
3e
Microprocessor vs.
Microcontroller (1)

3e
3e
Microprocessor vs.
Microcontroller (2)
 Microcontrollers are designed to perform specific
tasks. Specific means applications where the
relationship of input and output is defined.
Depending on the input, some processing needs
to be done and output is delivered. For example,
keyboards, mouse, washing machine, digicam,
pendrive, remote, microwave, cars, bikes,
telephone, mobiles, watches, etc. Since the
applications are very specific, they need small
resources like RAM, ROM, I/O ports etc. and hence
can be embedded on a single chip. This in turn
reduces the size and the cost.

3e
3e
Microprocessor vs.
Microcontroller (3)
 Microprocessor find applications where tasks are
unspecific like developing software, games,
websites, photo editing, creating documents etc.
In such cases the relationship between input and
output is not defined. They need high amount of
resources like RAM, ROM, I/O ports etc.
 The clock speed of the Microprocessor is quite
high as compared to the microcontroller. Whereas
the microcontrollers operate from a few MHz to
30 to 50 MHz, today’s microprocessor operate
above 1GHz as they perform complex tasks.

3e
3e
Microprocessors Microcontrollers
Microprocessor is the heart of
computer system.
It is the heart of the embedded
system.
It is just a processor. Memory and I/O
components have to be having to be
connected externally.
Microcontroller chip contains processor
along with internal memory and I/O
components.
Since I/O and memory connected
externally, the circuit becomes large.
Since I/O and memory present
internally, the circuit is small.
Can't be used in compact systems Can be used in compact systems
Cost of entire system increases. Cost of entire system is low.
Power consumption is high. Power consumption is low.
Most of the microprocessors do not
have power saving modes.
Most of the microcontrollers have
power saving mode.
Difficult to replace. Easy to replace.
Mainly used in personal computers. Used mainly in washing machine, MP3
players.

3e
3e
Discussion
 Why do we need microcontrollers?

3e
Characteristics of
Embedded Systems

3e
3e
Characteristics of embedded
systems
 Think about a real world embedded
device (say a GPS Navigator)
 Sophisticated functionality
 Real-time operation.
 Low manufacturing cost.
 Low power.

3e
3e
Functional complexity
 Often have to run sophisticated
algorithms or multiple algorithms.
 Cell phone, laser printer, automobile
engine control for fuel/pollution
efficiency
 Often provide sophisticated user
interfaces.

3e
3e
Real-time operation
 Must finish operations by deadlines.
 Hard real time: missing deadline causes
failure.
 Soft real time: missing deadline results
in degraded performance.
 Many systems are multi-rate: must
handle operations at widely varying
rates.

3e
3e
Cost and Power
 Many embedded systems are mass-
market items that must have low
manufacturing costs.
 Limited memory, microprocessor power,
etc.
 Power consumption is critical in
battery-powered devices.
 Excessive power consumption increases
system cost even in wall-powered
devices.

3e
3e
Discussion
 Which characteristic clearly
distinguishes the embedded systems
from traditional computing systems?

3e
Challenges in building
embedded systems

3e
3e
Challenges in embedded
system design
 How much hardware do we need?
 How big is the CPU? Memory?
 How do we meet our deadlines?
 Faster hardware or cleverer software?
 How do we minimize power?
 Turn off unnecessary logic? Reduce
memory accesses?

3e
3e
Challenges, etc.
 Does it really work?
 Is the specification correct?
 Does the implementation meet the
spec?
 How do we test for real-time
characteristics?
 How do we test on real data?
 How do we work on the system?
 Observability, controllability?
 What is our development platform?

3e
3e
Discussion
 What challenges did you face in your
senior design project?

3e
Performance
Considerations

3e
3e
What does “performance”
mean?
 In general-purpose computing,
performance often means average-
case, may not be well-defined.
 In real-time systems, performance
means meeting deadlines.
 Missing the deadline by even a little is
bad.
 Finishing ahead of the deadline may not
help.

3e
3e
Characterizing performance
 We need to analyze the system at
several levels of abstraction to
understand performance:
 CPU.
 Platform (Buses and I/O devices)
 Program (Software code)
 Task (multiple threads)
 Multiprocessor (multiple processors)

3e
Design Process Used for
Developing Embedded
System

3e
3e
Design Process: Levels of
abstraction
requirements
specification
architecture
component
design
system
integration

3e
3e
Requirements
 Plain language description of what
the user wants and expects to get.
 May be developed in several ways:
 talking directly to customers;
 talking to marketing representatives;
 providing prototypes to users for
comment.

3e
3e
Functional vs. non-functional
requirements
 Functional requirements:
 output as a function of input.
 Non-functional requirements:
 time required to compute output;
 size, weight, etc.;
 power consumption;
 reliability;
 etc.

3e
3e
Example: GPS moving map
requirements
 Moving map
obtains position
from GPS,
paints map
from local
database.
lat: 40 13 lon: 32 19
I-78
Scotch
Road

3e
3e
GPS moving map needs
 Functionality: For automotive use. Show
major roads and landmarks.
 User interface: At least 400 x 600 pixel
screen. Three buttons max. Pop-up menu.
 Performance: Map should scroll smoothly.
No more than 1 sec power-up. Lock onto
GPS within 15 seconds.
 Cost: $120 street price = approx. $30 cost
of goods sold.

3e
3e
GPS moving map needs,
cont’d.
 Physical size/weight: Should fit in
hand.
 Power consumption: Should run for 8
hours on four AA batteries.

3e
3e
Specification
 A more precise description of the
system:
- Requirements document what is needed - they shouldn't
specify the how, but the what.
- Specifications document how to achieve the
requirements - they should specify the how.
http://www.jrobbins.org/ics121f03/lesson-spec-design.html
 Another way to look at it is that the requirements represent
the application from the perspective of the user, or the
business as a whole. The specification represents the
application from the perspective of the technical team.
 https://
softwareengineering.stackexchange.com/questions/121289/what-is

3e
3e
GPS specification
 Should include:
 What data is received from GPS
satellites;
 How to get, store and show map data;
 user interface;
 operations required to satisfy user
requests;
 background operations needed to keep
the system running.

3e
3e
Architecture design
 What major components go
satisfying the specification?
 Hardware components:
 CPUs, peripherals, etc.
 Software components:
 major programs and their operations.
 Must take into account functional
and non-functional specifications.

3e
3e
GPS moving map block
diagram
GPS
receiver
search
engine
renderer
user
interface
database
display

3e
3e
GPS moving map hardware
architecture
GPS
receiver
CPU
panel I/O
display frame
buffer
memory

3e
3e
GPS moving map software
architecture
position database
search
renderer
timer
user
interface
pixels

3e
3e
Designing hardware and
software components
 Must spend time architecting the
system before you start coding.
 Some components are ready-made,
some can be modified from existing
designs, others must be designed
from scratch.

3e
3e
System integration
 Put together the components.
 Many bugs appear only at this stage.
 Have a plan for integrating
components to uncover bugs quickly,
test as much functionality as early as
possible.

3e
3e
Discussion
 What are the main lessons learned in
this chapter?

3e
3e
Arduino Introduction
 Arduino Tutorials
 https://
www.arduino.cc/en/Tutorial/HomePage
 Arduino Kit Simulation Environment
 https://www.tinkercad.com/circuits
 http://circuits.io
 https://
learn.sparkfun.com/tutorials/what-is-
an-arduino

3e
3e
Summary
 Embedded computers are all around
us.
 Many systems have complex embedded
hardware and software.
 Embedded systems pose many
design challenges: design time,
deadlines, power, etc.
 Design methodologies help us
manage the design process.

ch1_1_Introduction_To_Embedded_Systems.pptx.pdf

Recommended

Recommended

More Related Content

Similar to ch1_1_Introduction_To_Embedded_Systems.pptx.pdf

Similar to ch1_1_Introduction_To_Embedded_Systems.pptx.pdf (20)

Recently uploaded

Recently uploaded (20)

ch1_1_Introduction_To_Embedded_Systems.pptx.pdf