a semiconductor memory device includes a controller , a plurality of substrates , and a plurality of stacked memories that are spaced apart and sequence on each of the substrates . each of the stacked memories includes an interface chip that is connected to the respective substrate and a plurality of memory chips that are stacked on the interface chip . the controller is configured to control the stacked memories . the interface chips are configured to forward a command signal from the controller through each interface chip in the sequence of stacked memories that is intervening between the controller and a selected stacked memory to which the command signal is directed . the interface chips may forward the command signal from one end of the sequence of the stacked memories on one of the substrates to the selected stacked memory , and forward a response signal from the selected stacked memory through the remaining stacked memories in the sequence on the substrate back to the controller or through the same sequence of stacked memories that was taken by the command signal .