Transcript Embedded Systems (Limjoco/Thong-Ngam)

Embedded Systems Development
Presented by:
Christian Limjoco
Sineenart Thong-Ngam
What is an Embedded System (E.S.)?
Embed:
Definition 1: to fix (something) firmly and
deeply (Longman Dictionary)
Definition 2: To fix firmly in a surrounding
mass(Dictionary.com)
System: implicitly a controlling system.
Embedded System: any device that includes a
programmable computer but is not itself a
general-purpose computer
Purpose of Embedded System (E.S.)
• Embedded systems are systems that possess
capabilities, which are resident on operational
equipment or are interfaced with it.
• The objective of this focus area is to enhance
readiness through expanded training and testing
opportunities using embedded systems.
Key Difference with PCs
• React to external events that may be
particularly rapid
- Anti-lock brake system (ABS): pumps brakes
to reduce skidding.
- Missile flying at low altitude over a
mountainous area
• Must handle unusual events
- A user blocking an elevator door, power
blackout,memory failure
• Does not use an insulation (shell) between the
program and the hardware.
Products with embedded systems
• Personal digital assistant (PDA).
• Printer.
• Cell phone.
• VCRs, DVD players.
• Microwave.
• Washer.
• Camera.
• Printers, copiers.
Early History
• Late 1940’s: MIT Whirlwind computer was
designed for real-time operations.
• 1948: ENIAC(electronic numerical integrator
and computer) the world's first electronic
digital computer used for Smart Bombs
• 1971: Intel 4004, first microprocessor (4bits),
initially for a calculator.
• 1972: Intel 8008, the first 8-bitter
• 1975: MOS Technology introduced the 6502 at
the astonishing price of $25. That sparked the
Jobs/Wozniak whiz kids to develop the Apple
computer.
Early History (continued)
• Mid 1970s: Automobiles used
microprocessor- based engine controllers
• 1981: The PC revolution begins IBM
introduced the PC. Using a 4.77MHz 8088
and limited to 640KB of RAM, this machine
caused the entire world to take notice of
the microprocessor industry.
• Microprocessors get so cheap that
microprocessor-based control systems
become the rule.
• Only limit: processing time.
General Principles & Philosophy
Vitruvian Triad: Function, Form and Fabrication
• Firmitas (Soundness) – The materials used
must be carefully chosen but not with excessive
frugality.
• Utilitas (Utility) – The design of an artifact
should allow faultless unimpeded use through the
disposition of the spaces and the allocation of
each spaces and allocation of each type of space
is properly oriented, appropriate, and comfortable.
General Principles & Philosophy
Vitruvian Triad: Function, Form and Fabrication
• Venustas (Attractiveness) – The appearance
of an artifact is pleasing and elegant, and the
proportions of its elements have properly
developed principles of symmetry.
General Principles & Philosophy
Principles of User Interface Design
Approaches to usability:
• Usability by Evaluation –involves
dissecting a design to find its strong
and weak points with a view to making
improvements.
• Usability by principles - is about deciding
ahead of time what usability properties will
be desirable on this interface, and what
types of people will use it.
General Principles & Philosophy
Principles of User Interface Design
• Robustness
• Consistency
• Affordance
• Surface area
• Compatibility
• Directed interfaces
• Multithreading
• Modes
• Equal opportunity
• Multiple paths
• Migrating from mechanical controls
Embedded Systems Lifecycle
Embedded Systems Lifecycle
• Product Specification- The product
specification phase involves doing research
on customers. Most companies accomplish
this by using focus groups or questionnaires
through their marketing departments.
• Hardware/Software Partitioning- Designing and
embedded system involves both hardware and
software components. It is important for an
engineer to decide which portion of the problem
will be solved through hardware and which
through software.
Embedded Systems Lifecycle
• Iteration and Implementation - It is in this phase that
development teams have a greater opportunity to get
everything right the first time, and minimize the risk of
discovering an error late in design which always leads to
schedule backlogs.
• Detailed Hardware and Software Design - In this phase,
the embedded systems developer must define the runtime environment. The embedded systems developer
must decide where the various components will reside
(in RAM, ROM, or flash memory) and how they will be
packaged and scheduled.
Embedded Systems Lifecycle
• Hardware/Software Integration - The hardware/software
integration phase of the development cycle deals with
two primary activities, discovery and debugging.
• Product Testing -The testing and reliability requirements
for an embedded system are much more stringent than
the vast majority of desktop applications. Testing
involves more than making sure the software doesn’t
crash at a critical moments .
• Maintaining and Upgrading Existing Products- This
phase of embedded systems design lifecycle involves
the use of tools that are specifically used for reverse
engineering and rapidly simulating scenarios.
The need for a methodology
• There are engineers that have brilliant ideas for standard
procedures and applied them. However, when these
“heroes” leave the company the techniques and
methodology left with them.
• When companies used established procedures
documentation for this is disorganized consisting of
scattered notes and files. It is also rarely found in one
place.
• Even in companies that followed a defined procedure,
often parts of a procedure are not well understood or
completely implemented
• Consultants often find themselves needing to reuse
some general process patterns for each new design they
make for companies of varying sizes.
Universal Design Methodology
Universal Design Methodology
• Write a specification - Defines the entire design and
each person’s responsibility. By creating a specification,
an engineer may be able to design a correct interface
for the rest of the chip, save time and thus costs avoids
misunderstandings.
• Specification Review - This phase is important in finding
out whether there is something wrong or something has
been left out the specification.
• Choosing technology and tools - Deciding on the device
and tools early on is critical for the embedded systems
development project. A chosen synthesis tool will test
algorithms in different conditions/states.
Universal Design Methodology
• Design – The goal is to increase your chances of
producing a working, reliable device one that will work for
different chip vendor processes and continue to work for
the lifetime of your system
Design Techniques:
- Use top-down design
- Work with device architecture
- Do synchronous design
- Avoid floating nodes
- Avoid Bus Contention
Universal Design Methodology
• Verification - a “super phase” consisting of a group of
methods and techniques used to detect design errors
before a chip is created.
 Simulation - Helps determine that your chip will
function correctly in your system.
Design review - This is one of the most important
reviews. It determines if a chip will work correctly in
your system.
Synthesis - Involves specifying switches and
optimization criteria in the Hardware Description
Language code, or using synthesis software in order to
ensure good timing and utilization.
Universal Design Methodology
• Verification (continued)
Place and Route - This is one of the most important
reviews. It determines if a chip will work correctly in
your system.
Formal Verification - The formal verification that
takes place at this stage is known as equivalency
checking. This kind of formal verification involves a
software tool that performs a mathematical comparison
of the functionality of both circuits in order to confirm
that both circuits will operate correctly.
Universal Design Methodology
• Final review -The final review of the chip should be a
formality at this point. If the design team has followed all
of the other steps and the other reviews have taken
place, this review should be a simple sign-off that
verifies that the design has been coded, simulated,
synthesized, laid out and routed, and is now ready to go
into the system.
• System Integration and Test -Integration and system
testing is necessary at this point to ensure that all parts
of the system work correctly together. When the chips
are put into production, the production process should
include some sort of burn-in test that continually tests the
system over some long amount of time
• Ship Product
Benefits of UDM
Value Proposition:
• The Universal Design Methodology as it relates
specifically to programmable devices ensures the proper
design, review, and testing of your product. It aims to:
 Design a device that is free from defects, works
reliably over the lifetime of the device and functions
correctly in your system
 Efficiently design this device: In the least amount of
time, using the least amount of resources including
personnel.
 Plan the design efficiently: Create a reasonable
schedule as early in the process as possible.
Know all necessary resources up front and allocate
them as early in the process as possible.
Success Factors
• Product Planning
 Know the users and their needs
Freeze the product requirements
Be mindful of the product lifecycle
• Engineering
Electromagnetic compatibilities should be considered
from the start.
Reasonable accommodations should be made for
future a requirements.
Safety and Hazard Issues should be Reviewed Early
and Often.
Plan for two or three revision boards.
Success Factors
• Design for Testability
• Custom vs. Off the shelf
• Evaluate Technical Support
• Outsourcing
Challenges
•
•
Analog circuitry reliability, security, connectivity, and
device manageability have become critically
important for digital embedded systems.
Threatens health and safety
 For example, a potential malfunction in the
embedded digital technology that runs a
major control system for a chemical refinery
or a nuclear power plant.
Market data/forecasts
Marketplace Analysis
• Wind River
• Founded in 1981, Wind River is headquartered in
Alameda, California, with operations worldwide
• Aerospace and defense, automotive, digital
consumer, industrial, and network infrastructure.
Marketplace Analysis
• The MathWorks
• Founded in 1984 and is headquartered in Natick,
Massachusetts, with offices and representatives
throughout the world.
• The fundamental tools for the engineering and
scientific work
Marketplace Analysis
• The Green Hills
• Green Hills is 20 years old, privately held, profitable
since its inception, and is growing at an average rate
of 30% per year.
• The world's #2 RTOS company