Semiconductor memory device and control method for semiconductor memory device

Abstract

Provided is a semiconductor memory device using a single-bit line method that determines read operation timing in accordance with operation of a replica bit line. Further provided is a control method for the semiconductor memory device. Even when a transistor property fluctuation has occurred, the semiconductor memory device and the control method are capable of preventing, for example, increases in access time and circuit size and concurrently capable of reducing the occurrence probability of data readout error. The gate lengths of replica memory cell transistors are set as being values greater than the gate length of memory cell transistors. Thereby, a distribution center of a current drive capability distribution of the replica memory cell transistors is set lower than a distribution center of a current drive capability distribution of the memory cell transistors. Consequently, an occurrence probability of a delay in a voltage-fall start time on a regular data line can be reduced to be lower in comparison to a transmission timing of a latch control signal.