US Patent 7221614 Stacked semiconductor memory device

The stacked semiconductor memory device of the present invention has the object of reducing the cost of developing a wide variety of memory devices and includes: a memory cell array chip that is equipped with memory cell arrays, an interface chip that is stacked with the memory cell array chip and that is provided with a memory configuration switching circuit for changing the input/output bit configuration of the memory cell arrays, and a plurality of interchip wires for connecting the memory cell array chip and the interface chip.