A device includes a first semiconductor chip that includes a first memory cell array including a plurality of first memory cells, a first control logic circuit accessing the first memory cell array and producing a plurality of first data signals in response to data stored in selected ones of the first memory cells, a plurality of first data electrodes, and a first data control circuit coupled to the first control logic circuit and the first data electrodes. A second semiconductor chip includes a second memory cell array including a plurality of second memory cells, a second control logic circuit accessing the second memory cell array and producing a plurality of second data signals in response to data stored in selected ones of the second memory cells. The second control logic circuit is configured to store second timing adjustment information and to produce a second output timing signal.