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             Architecting Embedded Software 
             Using Model-Based Design
              Alan Moore                                                                                  .
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              The MathWorks                                                                               rk
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                                                                                                          2007 The
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            Overview
           ƒ Developing algorithmic models in Simulink
                ƒ Composing algorithmic models within the Simulink algorithmic 
                   architecture
                ƒ Deploying algorithmic models as software systems
           ƒ Integrating Simulink algorithmic models into a component-
              based architecture
                ƒ Translating algorithmic models into software components in a 
                   software architecture
                    ƒ Programming language as integrating medium
                    ƒ UML as integrating medium
                ƒ Integrating algorithmic models as components in an AUTOSAR 
                   software architecture
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               A Simple Algorithmic Model
              ƒ Twanted–desired                                       Temperature Control Algorithm
                  temperature
              ƒ Tactual – sensed 
                  temperature
              ƒ recycReq – recycle air                            1
                                                                distReq
              ƒ distReq – distribute heat                                          1
                                                                                   z                              Enable
                                                                                Unit Delay
                                                                  2
              ƒ ACAct–activate AC                               recycReq         Logical
              ƒ HeaterAct – activate                                                                    ACAct ACAct           1
                  heater                                          3                        SetPTemp                         AircoOn
                                                                Twanted                               HeaterAct HeaterAct     2
              ƒ RequiredTemp–heater                                                                                         HeaterOn
                                                                                                   RequiredTemp RequiredTemp  3
                  temperature                                     4                        IntTemp                           Tdiff
                                                                Tactual                              BlowerOut                4
              ƒ BlowerOut – fan speed                                                                         BlowerOut     BlowerOut
                                                                                                                                     3
      AM14
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            Technologies for Algorithm Composition
           ƒ Subsystems
                ƒ Interface propagation supports iterative approach
                ƒ Richer interface (enabled subsystem, function trigger ports)
                ƒ For prototyping and smaller algorithms
           ƒ Referenceable models
                ƒ Interface tightly specified so easier to export to other environments
                ƒ More modular and scaleable 
                ƒ Standalone so easier to integrate into external CM projects
                ƒ For larger algorithms and external deployment
           ƒ Both can be organized into libraries for reuse
           ƒ Automated conversion is available between the two representations
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