Timing Diagrams

Behavioral Modeling Diagrams

Timing Diagrams

Timing diagrams (UML 2.0) are a specific type of interaction diagram, where the focus is on timing constraints.

Timing diagrams are used to explore the behaviors of objects throughout a given period of time. A timing diagram is a special form of a sequence diagram. The differences between timing diagram and sequence diagram are the axes are reversed so that the time is increased from left to right and the lifelines are shown in separate compartments arranged vertically.

Timing diagrams are used to show changes and their relationship to clock times. It provides a visual representation of objects changing state and interacting over time.

Timing diagrams can be used for defining hardware-driven or embedded software components. The X-axis of the timing diagram normally has the time units with the Y-axis showing the objects and their states. States are normally changed by some sort of event that causes the state change. Timing diagrams can be drawn from a value or time based point of view.

Example: Time-based timing diagram

Example: Value-based timing diagram