Stateflow

at Temporal Logic Operator

The syntax for the at operator is as follows:

• at(n, E)
  

where E is the base event for the at operator and n is one of the following:

• A constant integer greater than 0
• An expression that evaluates to an integer value greater than or equal to 0

The at operator is true only at the n^th occurrence of the base event E since activation of its associated state. Otherwise, it is false. In a chart with no input events, at(n,wakeup) (or at(n,tick)) evaluates to true when the chart wakes up for the n^th time.

Note    The at operator resets its counter for E to 0 each time the associated state is activated.

The following example illustrates the use of the at operator in a transition expression.

• ROTATION[at(10, CLK)]
  

This expression permits a transition out of the associated state only if a ROTATION event occurs exactly 10 CLK cycles after activation of the state.

The next example illustrates usage of an at event in a state's during action.

• Heater_on
  on at(10, CLK): status('heater on');
  

This example causes the Heater_on state to display a status message 10 CLK cycles after activation of the associated state.

before Temporal Logic Operator

every Temporal Logic Operator