A memory device includes a first scalar register file storing a first input fragment, a second scalar register file storing a second input fragment, an arithmetic logic unit (ALU), and a control circuit. The control circuit is configured to perform, using the ALU, a first operation between the first input fragment and a first weight fragment based on a first operation command received from a host, and to perform, using the ALU, a second operation between the second input fragment and a second weight fragment based on a second operation command received from the host.