A semiconductor device includes a data detection circuit configured to detect a number of bits having a predetermined logic level among bits included in data to generate a detection signal. The semiconductor device also includes a selection/transmission circuit configured to output the detection signal or a control data signal as a pre-masking signal based on a selection/transmission signal. The semiconductor device further includes a masking signal generation circuit configured to latch the pre-masking signal based on a pipe input control signal and configured to output the latched signal of the pre-masking signal as a masking signal for controlling a data masking operation based on a pipe output control signal.