Semiconductor memory device, method of controlling read preamble signal thereof, and data transmission system

Abstract

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.

What is claimed is: 
     
         1 . A method for accessing a semiconductor memory device comprising:
 providing a system clock to a system clock input terminal of the memory device;   providing desired preamble length information to address input terminals of the memory device, wherein the desired preamble length information is a selected one of a plurality of possible preamble lengths;   providing a read command to command input terminals of the memory device;   receiving a preamble having a duration specified by the desired preamble length information from a bidirectional data strobe terminal of the memory device; and   receiving read data from bidirectional data terminals of the memory device in synchronization with a read toggle signal received from the bidirectional data strobe terminal of the memory device.