Currently it is not possible to define what happens when an undefined / illegal instruction is detected. To define such a behavior an annotation to an exception definition should be defined which specifies that this exception is raised when the decoder has no valid decode. The suggested name is [illegal instruction].
[illegal instruction]
exception UndefinedInstruction () = {
$GeneralException (ExceptionClass::Uncategorized, 0, PC, 0)
}
I suggest that the decoder generator gives an error, when no exception is defined for hardware generation. For simulator generation the definition of an exception should be optional, but if an exception with the annotation [illegal instruction] is available, the behavior defined in the exception is executed and the simulator does not raise a simulator exception.
Currently it is not possible to define what happens when an undefined / illegal instruction is detected. To define such a behavior an annotation to an exception definition should be defined which specifies that this exception is raised when the decoder has no valid decode. The suggested name is
[illegal instruction].I suggest that the decoder generator gives an error, when no exception is defined for hardware generation. For simulator generation the definition of an exception should be optional, but if an exception with the annotation
[illegal instruction]is available, the behavior defined in the exception is executed and the simulator does not raise a simulator exception.