semiconductor systems are provided . the semiconductor system includes a controller and a semiconductor memory device . the controller generates a first command signal and receives a foreground data to generate a foreground control signal for controlling a drivability of the foreground data and to generate a second command signal . the semiconductor memory device receives the first command signal to output a pattern data as the foreground data through a foreground input / output line , stores the foreground control signal therein in response to the second command signal , and controls the drivability of the foreground data according to the foreground control signal .