A non-volatile memory device includes an input/output terminal mixing section configured to couple data input/output terminals of the memory device to data input/output terminals of a page buffer in accordance with a user selection. A user data authenticating section is configured to transmit a control signal to the input/output terminal mixing section so that the input/output terminal mixing section couples the data input/output terminals of the memory device to the data input/output terminals of the page buffer in accordance with the user selection. A spare cell is configured to store the coupling configuration of the data input/output terminals of the memory device and the data input/output terminals of the page buffer in accordance with the user selection.