A semiconductor device includes an interface chip including: an internal data terminal, and a timing data storage circuit configured to output a plurality of timing set signals, and a plurality of core chips stacked with one another, each of the core chips including a plurality of memory cells, an output control circuit coupled to the timing data storage circuit of the interface chip, the output control circuit being configured to receive a corresponding one of the timing set signals and to output an output timing signal in response to the corresponding one of the timing set signals, and a data output circuit coupled to the internal data terminal of the interface chip, the data output circuit being configured to output data in response to the output timing signal, the data being derived from a corresponding one of the memory cells.