A semiconductor memory device including a clock buffer, a column selection
line decoder, a control signal generation circuit, and a column selection
line driver. 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.