Stateflow User's Guide

Setting Breakpoints for Debugging

A breakpoint indicates a point at which the Stateflow Debugging window halts execution of a simulating Stateflow diagram. At this time you can inspect Stateflow and MATLAB workspace data and examine the status of a simulating Stateflow diagram.

The Stateflow Debugging window supports global and local breakpoints. Global breakpoints halt execution on any occurrence of the specific type of breakpoint. Local breakpoints halt execution on a specific object.

Setting Global Breakpoints

Use the Breakpoint controls in the Stateflow Debugging window to specify global breakpoints. When a global breakpoint is encountered during simulation, execution stops and the Debugger takes control. Select any or all of the following global breakpoints:

• Chart Entry -- Simulation halts on chart entry.
• Event Broadcast -- Simulation halts when an event is broadcast.
• State Entry -- Simulation halts when a state is entered.

These breakpoints can be changed during run-time and are immediately enforced. When you save a Stateflow diagram, the breakpoint settings are saved with it.

Global breakpoints can be changed during run-time and are immediately enforced. When you save the Stateflow diagram, all the Stateflow Debugging window settings (including breakpoints) are saved, so that the next time you open the model, the breakpoints are as you left them.

Setting Local Breakpoints

You can set breakpoints for Stateflow objects that halt the execution of state actions, transitions, function calls, and event broadcasts.

1. In the Model Explorer, right-click a particular state, transition, function, or event.
2. From the resulting pop-up menu, select Properties.

1. A dialog appears for setting the properties of the object.

   You can also access the properties dialog for states, transitions, and functions in the Stateflow diagram editor by right-clicking on them and selecting Properties from the resulting pop-up menu. You can only access the properties dialog for an existing event in the Model Explorer.

3. Select from the following Debugger breakpoints options:

1. For states, select one of the following breakpoints:
   • State During -- Stop execution before state during actions are performed.
   • State Entry -- Stop execution before state entry actions are performed.
   • State Exit -- Stop execution before state exit actions are performed.

   For transitions, select one of the following breakpoints:

   • When Tested -- Stop execution before the transition is tested to see if it is a valid transition to take.
   • When Valid -- Stop execution after the transition tests valid, but before the transition is actually taken.

   For functions, select Function Call to stop execution before the function is called.

   For events, select one of the following breakpoints:

   • Start of Broadcast -- Stop execution before the event is broadcast.
   • End of Broadcast -- Stop execution after event is read by a Stateflow object.

Debugging with the Debugging Window

Setting Error Checking in the Debugging Window

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