Semiconductor memory device and data path using it

摘要

In the construction used until now, multiport memories have, for example, the disadvantage that the ratio between the number of rows and the number of columns is not freely selectable and that, if there is a relatively large number of words, the bit line length is increased, which in turn means that there are disadvantages such as an increased delay time and increased charging and discharging currents. The semiconductor memory device according to the invention has multiple ports for the simultaneous writing and reading of data. A memory cell field has a plurality of memory cells (1), which are arranged in rows and columns, write and read word lines (WW, RW), which are connected to the memory cells of the respective rows, and write and read bit lines (WB, RB), which are connected to the memory cells of the respective columns. The data input takes place via write circuits (3i), and the data output takes place via read amplifiers (4i). The write word line, the write bit line and the input terminal (DI) form a first port, while the read word line, the read bit line and an output terminal (DO) form a second port. The invention can be used for multiport memories. <IMAGE>