嵌入式系统导论-实验课-3-slides.pdfVIP

1 Swiss Federal Institute of Technology Computer Engineering and Networks Laboratory Introduction to Embedded Systems Exercise 3: StateCharts Kai Huang huangk@in.tum.de 07.11.2014 2 Swiss Federal Institute of Technology Computer Engineering and Networks Laboratory StateCharts ? Specification model ? Suitable for complex systems, since they can model hierarchy and concurrency ? Transitions can be guarded by conditions ? Transitions can be associated with actions 3 Swiss Federal Institute of Technology Computer Engineering and Networks Laboratory Basic States and Super-States ? Basic States: states not composed of other states ? Super-States: states containing other states S: Super-State E: Basic State E: Sub-State of S S: Ancestor State of E 4 Swiss Federal Institute of Technology Computer Engineering and Networks Laboratory Hierarchy: OR-Super-States ? OR-Super-State: ? a Super-State A in which exactly one of its (immediate) sub-states (X, Y, Z) is active whenever A is active Y Z X A sub-states are related by “exclusive-or” 5 Swiss Federal Institute of Technology Computer Engineering and Networks Laboratory Concurrency: AND-Super-States ? AND-Super-State: ? a Super-State A in which all its (immediate) sub-states (B, C) are active whenever A is active A X Y B C sub-states are related by “and” 6 Swiss Federal Institute of Technology Computer Engineering and Networks Laboratory Tree Representation A B E C D F M G H I K L C: Basic State B: OR-Super-State A: AND-Super-State ? Super-States have at least one children ? Basic States have no children 7 Swiss Federal Institute of Technology Computer Engineering and Networks Laboratory Set of States ? Basic States ? State ? OR-Super-States ? Union of children ? AND-Super-States ? Cartesian product of children (computed traversing the tree from leaves to root) 8 Swiss Federal Institute of Technology Computer Engineering and Networks Laboratory Edge Labels ? Events: exist only until next model evaluation ?