Stateflow

Semantics of Active and Inactive States

This example shows the semantics of active and inactive states

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Initially the Stateflow diagram is asleep and both states are inactive. An event occurs and the Stateflow diagram is awakened. This is the semantic sequence:

1. The Stateflow diagram root checks to see if there is a valid transition as a result of the event. A valid default transition to state A is detected.
2. State A is marked active.
3. State A entry actions execute and complete (entA()).
4. The Stateflow diagram goes back to sleep waiting to be awakened by another event.

Event E_one occurs and the Stateflow diagram is awakened. State A is active. This is the semantic sequence:

1. The Stateflow diagram root checks to see if there is a valid transition as a result of E_one. A valid transition is detected from state A to state B.
2. State A exit actions execute and complete (exitA()).
3. State A is marked inactive.
4. State B is marked active.
5. State B entry actions execute and complete (entB()).
6. The Stateflow diagram goes back to sleep, to be awakened by the next event.
   
   

Event-Driven Effects on Semantics

Semantics of State Actions