The document discusses the challenges in embedded system design, including optimizing hardware components to meet performance and power metrics, reducing power dissipation through techniques like clock rate reduction and disabling unused units, and meeting process deadlines while minimizing resources. It also covers ensuring flexibility, reliability through testing and validation, using modules that do not interfere with each other, and representing the system design formally using methods like the Unified Modeling Language.

1. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
1
Lesson 9:Lesson 9: Challenges in EmbeddedChallenges in Embedded
System Design: Optimizing the DesignSystem Design: Optimizing the Design
Metrics and Formalism of SystemMetrics and Formalism of System
DesignDesign

2. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
2
Amount and type of hardware needed
Optimizing the microprocessors, ASIPs and
single purpose processors in the system
Optimizing according to the performance,
power dissipation, cost and other design
metrics the system
Optimizing hardware (memory RAM, ROM
or internal and external flash or secondary
memory in the system, peripherals and
devices internal and external to the system,
ports and buses in the system and power
source or battery in the system).

3. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
3
Taking into account the design metricsTaking into account the design metrics
Design metrics examples –power
dissipation, physical size, number of
gates and engineering, prototype
development and manufacturing costs.

4. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
4
Optimizing the Power Dissipation
Clock Rate Reduction
Operating Voltage Reduction
Wait, Stop and Cache Disable Instructions –
Clever real- time programming. It is by
using of 'Wait' and 'Stop' instructions and
disabling or controlling certain units when
not needed is one method of saving power
during program execution

5. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
5
Disable use of certain structural units ofDisable use of certain structural units of
the processor to reduce power dissipationthe processor to reduce power dissipation
Caches—when not necessary and
Keep in disconnected state those structure
units that are not needed during a particular
software-portion execution, for example,
display screen, timers or IO units
Control of power requirement, for example,
by screen auto-brightness control

6. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
6
Meeting the deadline of all processes
in the system while keeping the
memory, power dissipation, processor
clock rate and cost at minimum is a
challenge
Process DeadlinesProcess Deadlines

7. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
7
Flexibility and Upgradeability
Ability to offer the different versions
of a product for marketing and offering
the product in advanced versions later
on.

8. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
8
ReliabilityReliability
Designing reliable product by appropriate
design and thorough testing, verification
and validation is a challenge.

9. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
9
Testing, Verification and ValidationTesting, Verification and Validation
Testing – to find errors and to validate that
the implemented software is as per the
specifications and requirements to get
reliable product.
Verification – refers to an activity to ensure
that specific functions are correctly
implemented.
Validation – refers to an activity to ensure
that the system that has been created is as
per requirements agreed upon at the
analysis phase, and to ensure its quality

10. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
10
ModulesModules
Be clearly understood and maintain
continuity.
Appropriate protection strategies are
necessary for each module. A
module is not permitted to change or
modify another module functionality.
For example, protection from a
device driver modifying the
configuration of another device

11. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
11
Formalism of System DesignFormalism of System Design

12. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
12
Formalism of Steps
Requirements and Specifications of
hardware and software
Define architectures of hardware and
software
Coding and implementation as per
architecture
Testing, validation and verification of
system

13. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
13
Diagrammatic modelDiagrammatic model
UML (Universal Modeling
Language)

14. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
14
UML (Universal Modeling Language)UML (Universal Modeling Language)
Conceptual design modeling
Classes and Objects to describe identity,
attributes, components and behaviour
– Inheritances in classes and objects
– Interfaces with the objects and their
implementation in the objects,
Structural description of the design
components

15. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
15
UML (Contd.)
– Behavioral description in terms of
states, state machine and signals
– Events description

16. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
16
Disable use of certain structural units ofDisable use of certain structural units of
the processor to reduce power dissipationthe processor to reduce power dissipation
Caches—when not necessary and
Keep in disconnected state those structure
units that are not needed during a particular
software-portion execution, for example,
display screen, timers or IO units
Control of power requirement, for example,
by screen auto-brightness control

17. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
17
Meeting the deadline of all processes
in the system while keeping the
memory, power dissipation, processor
clock rate and cost at minimum is a
challenge
Process DeadlinesProcess Deadlines

18. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
18
Flexibility and Upgradeability
Ability to offer the different versions
of a product for marketing and offering
the product in advanced versions later
on.

19. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
19
ReliabilityReliability
Designing reliable product by appropriate
design and thorough testing, verification
and validation is a challenge.

20. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
20
Testing, Verification and ValidationTesting, Verification and Validation
Testing – to find errors and to validate that
the implemented software is as per the
specifications and requirements to get a
reliable product.
Verification – refers to an activity to ensure
that specific functions are correctly
implemented.
Validation – refers to an activity to ensure
that the system that has been created is as
per the requirements agreed upon at the
analysis phase, and to ensure its quality

21. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
21
ModulesModules
Be clearly understood and maintain
continuity.
Appropriate protection strategies are
necessary for each module. A
module is not permitted to change or
modify another module functionality.
For example, protection from a
device driver modifying the
configuration of another device

22. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
22
We learnt
Challenges in system design
Meeting design metrics
Power dissipation reduction
Enabling and controlling of processes
and hardware units
Flexibility, upgradeability and
reliability
SummarySummary

23. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
23
We learnt
Formalism of System design Processes
Use of UML for diagrammatically
modeling the system design Processes
SummarySummary

24. 2008
Chapter-1: "Embedded Systems - " , Raj Kamal,
Publs.: McGraw-Hill Education
24
End of Lesson 9End of Lesson 9