A system, includes a controller comprising a plurality of first external terminals configured to supply a command and an address, and communicate a data, and communicate a strobe signal related to the data; and a semiconductor memory device including a plurality of second external terminals corresponding to the plurality of first external terminals, at least one of the plurality of first external terminals and at least one of the plurality of second external terminals each being capable of supplying an information specifying a length of a preamble of the strobe signal before the semiconductor memory device communicates the data between the controller and the semiconductor memory device, the semiconductor memory device further including a preamble register configured to be capable of storing the information.