Data is stored into a plurality of first memory blocks, and regeneration data for regenerating this data is stored into a second memory block. Adverse effects associated with a terminal capacitance from the large area PIN diode may be minimized by maintaining a relatively constant voltage across the input terminals of the amplifier. Thus, the present invention provides a TFT substrate in which a characteristic of a TFT is improved. The second address of the source telephone is retrieved by the target telephone in symmetrical manner.