Stateflow

Before Operator

Syntax

before(n, E)

where E is the base event for the operator and n is any expression that evaluates to a positive integer value.

Semantics

The before operator is true if the base event E has occurred less than n times since the operator's associated state was activated. Otherwise, it is false.

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

Usage

The following example illustrate use of the before operator in a transition expression.

ROTATION[before(10, CLK)]

This expression permits a transition out of the associated state only on occurrence of a ROTATION event but no later than 10 CLK cycles after activation of the state.

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

Heater_on
on before(MAX_ON_TIME, CLK): temp++;

This example causes the Heater_on state to increment the temp variable once per CLK cycle until the MAX_ON_TIME limit is reached.

After Operator

At Operator