EECE 276 Embedded Systems - School of...

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EECE 276 – Embedded Systems 1 EECE 276 Embedded Systems Documentation techniques A case study

Transcript of EECE 276 Embedded Systems - School of...

EECE 276 – Embedded Systems 1

EECE 276Embedded Systems

Documentation techniquesA case study

EECE 276 – Embedded Systems 2

Overall document structureIntroduction What?

Purpose Why?Scope Scope of systemDefinitions, Acronyms, Abbreviations ListsReferences Standards, etc.Overview

Overall Description Big pictureProduct Perspective InterfacesProduct Functions What It doesUser Characteristics User categoriesConstraints LimitationsAssumptions and Dependencies

Specific Requirements External interfaces, main classes,performance, timing

Appendices

EECE 276 – Embedded Systems 3

Traffic Light Control System

From textbook (Laplante ’04)

EECE 276 – Embedded Systems 4

Traffic Light Control System

From textbook (Laplante ’04)

EECE 276 – Embedded Systems 5

Traffic Light Control System

From textbook (Laplante ’04)

Overall Description

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Traffic Light Control SystemProduct Perspective

System InterfacesUser interfacesHardware interfacesSoftware interfacesCommunication interfacesMemory constraintsOperations

Product functionsUser characteristics

PedestriansMotor vehiclesTraffic Regulatory PersonnelSystem Administrators

ConstraintsRegulatory policyNetwork protocols…

AssumptionsSI unitsCommercial RTOS…

EECE 276 – Embedded Systems 7

Traffic Light Control System

From textbook (Laplante ’04)

Hardware Interfaces

EECE 276 – Embedded Systems 8

Traffic Light Control System

From textbook (Laplante ’04)

Specific requirements:

Top-level use-case diagram

EECE 276 – Embedded Systems 9

Traffic Light Control System

From textbook (Laplante ’04)

Specific requirements:

Preliminary class diagram

EECE 276 – Embedded Systems 10

Traffic Light Control System

From textbook (Laplante ’04)

Specific requirements:

Sample class description

EECE 276 – Embedded Systems 11

Traffic Light Control System

From textbook (Laplante ’04)

Specific requirements:

Statechart for controller sequence

EECE 276 – Embedded Systems 12

Traffic Light Control System

From textbook (Laplante ’04)

Specific requirements:

Timing requirements

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Summary

Requirement analysis is critical for good system design» Errors made here are very hard to rectify later

Structured techniques are available» Small-scale: FSM, Statechart, Petri-Net» Large-scale: Functional, OOAD

Requirement documents capture essential information» Format and content are often regulated by

government agencies (FAA, DoD, NASA)