Define Embedded Systems

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Define Embedded Systems
Small (?) Application Specific Computer Systems
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Typical Characteristics

• Real time
• Small sized
• Low power
• Cost effective

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Heterogeneous HW/SW Implementations of Embedded
Systems
Additionally, flexibility and tight time to
market requirements favour SW implementations.
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System-on-Chip Design

• Current day embedded systems utilize customized
  embedded processors
• Embedded processors have System-on-Chip (SoC)
  architectures
• SoC incorporate several different discrete cores
  on the same die.
• SoC design methodology strongly mirror
  board-level design.
• Hence, system-level hardware-software co-design
  has also been utilized for SoC design.
• This course will utilize platform FPGAs as a
  vehicle for SoC design.

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Control Intensive versusComputation intensive

• Control intensive application offer less
  opportunities
• for parallelism as opposed to computation
  intensive
• applications.
• Examples ???
• Hence, control intensive applications are more
• amenable for micro-controller implementation.
• Computation intensive applications are more
• amenable to custom-hardware (ASIC) or
• FPGA implementation.

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Define Hardware-Software Codesign
It is the concurrent and co-operative design of
hardware and software components of an embedded
system.
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HW Design Abstraction
Levels of Design Abstraction
Polygons of Silicon
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Digital System Design
Translation or Design
Verification by Simulation
Specification
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Traditional System-level Design Flow
Informal Specification, Constraints
System model
Architecture design
HW/SW implementation
Fail
Prototype
Test
Success
Implementation
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Traditional System-level Design Flow

• Lack of system-level performance evaluation
• HW/SW specification implemented before
  performance/energy/cost verification
• Long system-level design times
• Expensive under performance/energy/cost failures
• Over-design is common

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System-level HW-SW Co-Design
Informal Specification, Constraints
Component profiling
System model
Architecture design
Performance evaluation
HW/SW implementation
Fail
Prototype
Test
Success
Implementation
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System-level HW-SWCo-design
IDEA
Constraints
Specification
Components (HW,SW)
System-level HW-SW Co-design
Interconnect and buses
HW behavior and components
SW behavior, RTOS, schedule policy and processors
Memory hierarchy and mapping
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Issues in System-level HW-SW Co-design

• Specification of functionality and constraints.
• Simulation of functionality.
• Components as building blocks
• SW processors DSP and Micro-controllers
• HW co-processors ASICs, FPGA
• Storage elements Cache, Scratchpad, SRAM, DRAM
• Interconnection elements Buses and arbiters
• Interface and I/O units DMA, UART, D/A, A/D,
• Wireless communication
• Software platform RTOS and scheduling

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Issues in System-level HW-SW Co-design

• Performance analysis (timing, power, area)
• Design and optimization (timing, power, area)
• Architecture selection processing elements,
• memory units and inter-connect.
• RTOS and schedule scheme.

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Attributes of Embedded computing

• Real-time Operation.
• Sensing Control.
• Low cost.
• Low power consumption.
• Dependable.
• Autonomous.

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Where Embedded Systems are Used..? 1
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Current Accomplishments

• Current Products
• Automotive Control
• Improved fuel efficiency.
• Avionics
• Navigation, Collision avoidance.
• Medical Monitoring Systems.
• Smart Homes.(washing machines, Clocks etc.).
• Future Uses
• Intelligent Highways.
• Chemical and Biological Sensors etc.

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An Embedded Control System Designers View
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A Customer View
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Specification

• A more precise description of the system
• should not imply a particular architecture
• provides input to the architecture design
  process.
• May include functional and non-functional
  elements.
• May be executable or may be in mathematical form
  for proofs.

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GPS specification

• Should include
• What is received from GPS
• map data
• user interface
• operations required to satisfy user requests
• background operations needed to keep the system
  running.

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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.

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GPS moving map block diagram
display
GPS receiver
search engine
renderer
database
user interface
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GPS moving map hardware architecture
CPU
display
frame buffer
GPS receiver
memory
panel I/O
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Processor Selection
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Processor selection
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Scope of Codesign
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Steps
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Steps Refined
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Map between behaviour and architecture
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