Replacing Hardware With Software Analysis and simulation of existing hardware using Discrete Event System Specification.

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Replacing Hardware With Software Analysis and
simulation of existing hardware using Discrete
Event System Specification.

• By Philip Felber
• Aman Gupta
• Imaduddin Mohammed
• Kwadwo Adomako
• November 27, 2001
• Prepared for Dr. James Stine
• ECE 587 Hardware / Software CoDesign
• Illinois Institute of Technology

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Replacing Hardware With Software

• Philip Set the scene

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Replacing Hardware With Software

• Large apartment buildings built in the seventies
  (before embedded computers) were equipped with
  custom electronic security and control systems.

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Replacing Hardware With Software

• Apartment Security Panel
• Security
• Package Notification
• Fire Alarm
• Emergency

Security On
Package
(loudspeaker)
OFF
ON
Security Key Switch
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Replacing Hardware With Software

• System components
• Apartment security panels (in each unit)
• Central communications controller
• Alarm readout at front desk
• Keypad terminal at receiving room

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Replacing Hardware With Software

• Today its increasingly hard to find both repair
  parts and technicians who understand this
  antiquated hardware.

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Replacing Hardware With Software

• With DEVS as a framework, this study analyzes
  and simulates a legacy security system and
  assesses opportunities to replace certain
  hardware components with software.

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Replacing Hardware With Software

• Aman DEVS

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Replacing Hardware With Software

• The Discrete Event System Specification (DEVS)
  environment is a system based simulation tool
  that provides expandability with modular and
  hierarchical features and flexibility.
• DEVS framework consists of
• real system
• model
• simulator
• experimental frame
• These are related by two relations
• modeling relation
• simulation relation

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Replacing Hardware With Software
Experimental frame
Source System
Simulator
Behavior database
Simulation Relation
Modeling Relation
Model
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Replacing Hardware With Software

• In the DEVS formalism, there are two models to be
  specified
• Atomic Model from which larger models are built
• Coupled Model

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Replacing Hardware With Software

• Atomic Model contains
• Set of input ports
• Set of output ports
• Set of state variables and parameters
• Internal transition
• External transition
• Output function

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Replacing Hardware With Software

• Coupled Model must contain
• Set of components
• Set of input ports
• Set of output ports
• Coupling specifications

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Replacing Hardware With Software

• Imaduddin Specific analysis

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Replacing Hardware With Software

• Modeling with DEVS

• Outline the functions.

Input Events
Output Events
States

• Identify the Input Events.

Key Position

• Identify Internal States.

Door Position

• Identify Output Events

Intrusion
Emergency
Fire
Package
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Replacing Hardware With Software

• Hierarchical Model of the System

Coupled Model
Central Communication Control
Alarms to front desk
Coupled Model
Apartment Panel
Package Notification from Receiving room
Atomic Model
Security Alarm
Emergency Alarm
Fire Alarm
Atomic Model
Key
Door
Atomic Model
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Replacing Hardware With Software

• Simulation

Start
Initialize States

• Event Driven Program

Wait For Input Event

• Modular

NO

• Multithreaded

Input Event Occurs
YES
Process the request Give output
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Replacing Hardware With Software

• For Example

Input Event
Output Event
Central Communication Control Module
PkgReceive Module
AptPanel Module
Package Arrival
Set package Light ON
State----------------? Pkg Before Input Event
?NO After Input Event -?Yes
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Replacing Hardware With Software

• Kwadwo Close the deal

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Replacing Hardware With Software

• What we have accomplished
• Analysis of the system with DEVS formalism.
• Choose which components we can replace with
  software.
• Simulate the system.
• The DEVS simulation may develop into the actual
  production program.

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Replacing Hardware With Software

• Advantages of our Design
• Our design makes the system faster.
• It provides room for further additions to the
  system.
• It is easier to maintain.

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Replacing Hardware With Software

• Whats yet to be done?
• Complete the simulation program of the system in
  java.
• Complete documentation of the project.

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Replacing Hardware With Software Summary

• Some parts of legacy hardware systems are
  candidates for emulation by software running on
  general purpose microprocessors.
• DEVS may be a useful tool for analysis and
  simulation.
• The DEVS simulation may develop into the actual
  production program.

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Replacing Hardware With Software Where To Get
More Information

• Zeigler, Praehofer, and Kim Theory of Modeling
  and Simulation Integrating Discrete Event and
  Continuous Complex Dynamic Systems, Academic
  Press, 2000.
• Search the NET for DEVS.
• www.ece.iit.edu/pfelber/devs/ibms/