Control logic

Control logic is a key part of a software program that controls the operations of the program. The control logic responds to commands from the user, and it also acts on its own to perform automated tasks that have been structured into the program. ^[1]

Model of a simple stopwatch^[2]

Control logic can be modeled using a state diagram ^[3], which is a form of hierarchical state machine. These state diagrams can also be combined with flow graphs to provide a set of semantics for describing complex control logic. ^[4] This mix of state diagrams and flow graphs is illustrated in the figure on the right, which shows the control logic for a simple stopwatch. The control logic takes in commands from the user, as represented by the event named “START”, but also has automatic recurring sample time events, as represented by the event named “TIC”.

1. ^ Smith, S.E.. "What Is Control Logic?". http://www.wisegeek.com/what-is-control-logic.htm. 
2. ^ Hamon, G., & Rushby, J. (2004). An Operational Semantics for Stateflow. Fundamental Approaches to Software Engineering (FASE) (pp. 229–243). Barcelona, Spain: Springer-Verlag.
3. ^ Tiwari, A. (2002). Formal Semantics and Analysis Methods for Simulink Stateflow Models.
4. ^ Hamon, G. (2005). A Denotational Semantics for Stateflow. International Conference on Embedded Software (pp. 164–172). Jersey City, NJ: ACM.