A memory device includes a buffer die configured to receive a first broadcast command and a second broadcast command from an external device; and a plurality of core dies stacked on the buffer die. The plurality of core dies include: a first core die including a first processing circuit, a first memory cell array, a first command decoder configured to decode the first broadcast command, and a first data input/output circuit configured to output data of the first memory cell array to a common data input/output bus under control of the first command decoder; and a second core die including a second processing circuit, a second memory cell array, a second command decoder configured to decode the second broadcast command, and a second data input/output circuit configured to receive the data of the first memory cell array through the common data input/output bus under control of the second command decoder.