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

A method for using a controller to access a memory device in a semiconductor memory system, the method comprising:

• providing a system clock from the controller;
• receiving the system clock on a system clock input terminal of the memory device;
• providing desired preamble length information from the controller, wherein the desired preamble length information is a selected one of a plurality of possible preamble lengths;
• receiving the desired preamble length information on address input terminals of the memory device;
• issuing a read command using the controller;
• receiving the read command on command input terminals of the memory device;
• accessing read data from a first memory bank of the memory device;
• providing a preamble having a duration specified by the desired preamble length information on a bidirectional data strobe terminal of the memory device;
• providing the read data from bidirectional data terminals of the memory device in synchronization with a read toggle signal provided on the bidirectional data strobe terminal;
• receiving, at the controller, the preamble having the duration specified by the desired preamble length information;
• and
• receiving, at the controller, read data from the bidirectional data terminals of the memory device in synchronization with receiving, at the controller, the read toggle signal from the bidirectional data strobe terminal of the memory device.