EECE 276 – Embedded Systems1EECE 276Embedded SystemsDocumentation techniquesA case studyEECE 276 – Embedded Systems2Overall document structureIntroduction What?Purpose Why?Scope Scope of systemDefinitions, Acronyms, Abbreviations ListsReferences Standards, etc.OverviewOverall Description Big pictureProduct Perspective InterfacesProduct Functions What It doesUser Characteristics User categoriesConstraints LimitationsAssumptions and DependenciesSpecific Requirements External interfaces, main classes,performance, timingAppendicesEECE 276 – Embedded Systems3Traffic Light Control System From textbook (Laplante ’04)EECE 276 – Embedded Systems4Traffic Light Control System From textbook (Laplante ’04)EECE 276 – Embedded Systems5Traffic Light Control System From textbook (Laplante ’04)Overall DescriptionEECE 276 – Embedded Systems6Traffic Light Control SystemProduct Perspective System InterfacesUser interfacesHardware interfacesSoftware interfacesCommunication interfacesMemory constraintsOperationsProduct functionsUser characteristicsPedestriansMotor vehiclesTraffic Regulatory PersonnelSystem AdministratorsConstraintsRegulatory policyNetwork protocols…AssumptionsSI unitsCommercial RTOS…EECE 276 – Embedded Systems7Traffic Light Control SystemFrom textbook (Laplante ’04)Hardware InterfacesEECE 276 – Embedded Systems8Traffic Light Control SystemFrom textbook (Laplante ’04)Specific requirements:Top-level use-case diagramEECE 276 – Embedded Systems9Traffic Light Control SystemFrom textbook (Laplante ’04)Specific requirements:Preliminary class diagramEECE 276 – Embedded Systems10Traffic Light Control SystemFrom textbook (Laplante ’04)Specific requirements:Sample class descriptionEECE 276 – Embedded Systems11Traffic Light Control SystemFrom textbook (Laplante ’04)Specific requirements:Statechart for controller sequenceEECE 276 – Embedded Systems12Traffic Light Control SystemFrom textbook (Laplante ’04)Specific requirements:Timing requirementsEECE 276 – Embedded Systems13SummaryO Requirement analysis is critical for good system design» Errors made here are very hard to rectify laterO Structured techniques are available» Small-scale: FSM, Statechart, Petri-Net» Large-scale: Functional, OOADO Requirement documents capture essential information» Format and content are often regulated by government agencies (FAA, DoD,