SEMICONDUCTOR MEMORY DEVICE AND MODULE THEREOF OPERATING IN HIGH FREQUENCY, ESPECIALLY OUTPUTTING DATA INCLUDING PREAMBLE THROUGH DATA LINES

摘要

PURPOSE: A semiconductor memory device and a module thereof operating in a high frequency are provided to assure setup and hold time margin of stable data during high frequency operation, and also to prevent time skew due to time delay in realizing the memory module. CONSTITUTION: The semiconductor memory device(600) receives a data read command by being synchronized to a clock signal from the external, and outputs data including preamble through a plurality of data lines by being synchronized to the clock signal. The preamble is added to the start part of the data and informs the start of data output. Preamble added to each data being output through the data lines have equal logic value each other.