An apparatus includes a first selector which selects a test data during a first operation mode, and selects a first input data during a second operation mode, a first latch circuit which latches an output signal of the first selector according to a first clock signal, a second selector which selects one from a second input data and an output signal of the first latch circuit, and a second latch circuit which latches the second input data sent from the second selector according to a second clock signal during the second operation mode, and passes through the output signal of the first latch circuit sent from the second selector during the first operation mode.