1. A computerized apparatus having a processor and a storage device, the apparatus comprising: a generator configured to generate and store instructions associated with a system-under-test (SUT), wherein said generator is configured to generate self modifying code; a simulator configured to simulate an execution of an instruction by the SUT, wherein said simulator is operatively coupled to: a rollover mode detector configured to determine whether the simulator is about to simulate an execution of a code that is generated by the self modifying code; and a code interpreter configured to interpret the code.