You can start the debugger from either a Simulink® model window or from the MATLAB® Command Window.
In a model window, on the Debug tab, select Breakpoints List > Debug Model.
The debugger graphical user interface opens. See Debugger Graphical User Interface.
Continue selecting toolbar buttons.
When running the debugger in graphical user interface (GUI) mode, you must explicitly start the simulation. For more information, see Start a Simulation.
In the MATLAB Command Window, enter either
In both cases, the example model
vdp loads into memory, starts
the simulation, and stops the simulation at the first block in the model execution
The debugger opens and a debugger command prompt appears within the MATLAB command window. Continue entering debugger commands at this debugger prompt.