Semiconductor memory device and data bus amplifier activation method for

Abstract

In a data bus amplifier activation method for a semiconductor memory device having a memory cell array, a column selection circuit for selecting a column in the memory cell array, a read data bus for transferring read data, output from the column selected by the column selection circuit, to a read data bus amplifier, and a write data bus for transferring write data, output from a write data bus amplifier, to the column selected by the column selection circuit, the read data bus amplifier or the write data bus amplifier is activated by detecting the selection of the column effected by the column selection circuit. By so doing, a read data bus amplifier enable signal or a write data bus amplifier enable signal can be generated after the occurrence of a column select signal, eliminating the need to allow a large margin for the generation timing of the read data bus amplifier enable signal or the write data bus amplifier enable signal, and as a result, the operating speed of the semiconductor memory device can be increased.