The SVM simulator supports low-level debugging. Its debug mode is entered whenever the user inputs the ``debug'' special event. If the simulation makes use of a model-specific interface, the debug mode may be entered in a different way. For example, the CDPlayer example in the SVM distribution provides a ``Debug'' button that switches to the debug mode.
When the debug mode is entered, the simulation is suspended. The user is allowed to execute arbitrary Python code. If the default curses interface or the default graphical interface is used, the Python code entered by the user is highlighted according to a combined syntax of Python and SVM model description.
The Python code executed in the debug mode may inspect the status of the simulation and the model running in it, as well as modify their variables. eventhandler is an important object that contains most information concerning the simulation. Its following attributes are useful for debugging: