The present invention generally relates to a dynamic RAM (Random Access Memory) and, more particularly, to a technique which is effective for use in a dynamic RAM based on divided word line design having a main word line and a sub word line for example.
A divided word line design has been proposed in which a plurality of sub word lines, to which memory cells are connected, for a main word line, are arranged to operate only a memory block in which a memory cell to be selected is arranged, to minimize the memory area to be operated, so as to achieve reduced power consumption and increased speed in a selecting operation of the sub word lines to which memory cells are connected. One example of this divided word line design is disclosed in Japanese Unexamined Patent Publication No. Hei 2-158995. A method of arranging a signal line for sub word selection is disclosed in U.S. Pat. No. 5,359,572.