JPS6419587A - Semiconductor memory device - Google Patents

Abstract

PURPOSE:To realize a read or a write operation by one data bus line, by constituting a device so that the switching of the readout or the write of the data bus line can be performed by a transfer gate. CONSTITUTION:A read bus line RWB is commonly used for a read bus line and a write bus line. Firstly, since a write enable internal signal, the inverse of WE' is set at a high level and a WE' at a low level at the time of readout, a MOSFETQ1 is turned on, and a MOSFETQ2 is turned off. In other words, since a DIN buffer circuit 8 is cut off electrically, the bus line RWB functions as the lead bus line. Next, at the time of write, the signal, the inverse of WE' is set at the low level and the WE' at the high level, therefore, the FETQ1 is turned off and the Q3 turned on. Namely, since a sense amplifier circuit 5 is cut off electrically, the bus line RWB functions as the write bus line.