A microcontroller includes a signal interface for transmitting signals. The microcontroller further includes an error injection module. The error injection module is configured to tap a transmission signal associated with the signal interface. The error injection module includes a synchronization unit. The synchronization unit is configured to detect within the tapped transmission signal an occurrence of a synchronization event. Further, the error injection module is configured to modify the tapped transmission signal by adding at least one disturbance to the transmission signal in synchronization with at least the detected occurrence of the synchronization event.