Semiconductor memory device

Abstract

A semiconductor memory device having a plurality of bits includes an input buffer for receiving external data, a first write circuit for inputting a first control signal, and an output of the input buffer, and outputting the result on a first data line. A second write circuit inputs a second control signal and the result from the first data line, and outputs another output on a second data line. In a data writing operation, the second control signal is used commonly for at least two bits. The first write circuit sets the first data line to a fixed potential state when the first control signal is effective. In response to the fixed potential status on the first data line, the second write circuit sets the second data line to a potential state in which the second control signal is disregarded. A write per bit mode operation is controlled by controlling the second write circuit through a first data line. A control signal for controlling the write circuits can be used commonly for a plurality of bits, so that the number of control signals for controlling the write circuits can be reduced and thereby a pattern area required for wiring can be reduced.