TEST CIRCUIT FRO SEMICONDUCTOR MEMORY DEVICE

PURPOSE:To attain the propriety of judgment at every data by changing over a switch according to whether an expected value is coincident with the data input signal or not, thereby outputting the data selective signal. CONSTITUTION:When the data input signal D coincides with the expected value, the switch SW2 is turned off based on the data selective signal ST, and the expected value is outputted as it is from an output signal line S. When the data input signal D being in the inverse phase is not coincide with the expected value, the switch SW2 is turned on based on the data selective signal ST, and a fail signal line and the output signal line S are made conductive. Consequently, the level of the output signal line S changes to the level of the fail signal line holding steadily the level of inverse phase for this output signal line S. There fore, the level of inverse phase for the expected value is outputted from the output signal line S. In such a manner, with a pair of data input signals from one bit the test is carried out.