DRAM with bidirectional global bit line - has global bit lines joined to local bit lines to create bidirectional data access path for writing data to or reading from cell

摘要

The DRAM includes a number of cell blocks. Multiple local bit lines (1, 2, 3, 4) are connected respectively to cells in the cell blocks. First and second precharge circuits (40, 41) are connected to one side of the local bit lines. Global bit lines (5, 6, 7, 8) are arranged on the left side and right side of both adjacent local bit lines. The global bit lines are connected to the local bit lines and are commonly joined on to the local bit lines to read data stored in the cells or write data into the cells in a bidirectional data access path. ADVANTAGE - Permits bidirectional reading and writing of data stored in the memory cells. Has improved packing density and improved S/N characteristic.