Semiconductor memory device

Abstract

In a synchronous DRAM required to be capable of performing high-speed consecutive operations in synchronism with a clock signal, a DBI-line pair is connected between a DQ-line pair and an RDB-line pair, and pipeline operation whose single cycle time is divided into four periods is employed. This S-DRAM has following: a first precharge circuit for precharging or voltage-equalizing the DQ-line pair to a power supply voltage level in the first and forth periods only; a second precharge circuit for voltage-equalizing the DBI-line pair to a ground voltage level in the first and second periods only; a third precharge circuit for voltage-equalizing the RDB-line pair to the power supply voltage level in the first and second periods only; first and second differential amplifiers for transmitting data on the DQ lines onto the DBI lines in the third period and for holding the data on the DBI lines in the fourth period; and a third differential amplifier which transmits the data on the DBI lines onto the RDB lines in the third period and which holds the data on the RDB lines in the fourth period.