A semiconductor memory device including a clock buffer, a column selection
line decoder, a control signal generation circuit, and a column selection
line driver is provided. The clock buffer receives an external clock
signal and information about a column address strobe (CAS) latency and
generates either a first clock signal which synchronizes with rising
edges of the external clock signal or a second clock signal which
synchronizes with falling edges of the external clock signal depending on
the type of CAS latency information. The column selection line decoder
receives and decodes a column selection address and outputs a decoding
address used to select either a column selection line signal synchronized
with the first or second clock signal. The control signal generation
circuit outputs control signals that synchronize with one of the first
and second clock signals. The column selection line driver drives the
column selection line signal in synchronization with one of the first and
second clock signal in response to the decoding address and the control
signals.