A high-density semiconductor device includes a first input/output line connected among a plurality of banks on a core area storing data, so that it transmits data, a second input/output line connected to a data pad capable of performing data input/output operations at a Peri-area, so that it transmits data, a first repeater connected between the first input/output line and the second input/output line, for transmitting data of the first input/output line to the second input/output line in response to a read enable signal enabled by a read command, and a second repeater connected between the first input/output line and the second input/output line, for transmitting data of the second input/output line to the first input/output line in response to a write enable signal enabled by a write command.