Semiconductor memory device allowing increase in capacity and operation speed with a suppressed layout area

摘要

A column select gate of a semiconductor memory device includes read gate circuits. Each read gate circuit includes read gate transistors. Each read gate transistor connects a read column select line to a global I/O line pair in response to a potential level on a bit line pair received on its gate and the potential on the read column select line. A voltage drop caused on one of the paired global I/O lines by turn-on of the read gate transistor is amplified by a main read amplifier to obtain read data.