A semiconductor device includes a system-on-chip (SOC) and at least one wide input/output memory device. The SOC includes a plurality of SOC bump groups which provide input/output channels, respectively, independent from each other. The at least one wide input/output memory device is stacked on the system-on-chip to transmit/receive data to/from the system-on-chip through the SOC bump groups. The SOC bump groups are arranged and the at least one wide input/output memory device is configured such that one of the wide input/output memory devices can be mounted to the SOC as connected to all of the SOC bump groups, or such that two wide input/output memory devices can be mounted to the SOC with each of the wide input/out memory devices connected a respective half of the SOC bump groups.