Semiconductor memory device having refresh circuit and word line activating method therefor

Abstract

A semiconductor memory device includes a memory cell array having at least one memory bank. The memory bank being divided into memory blocks such that the memory blocks have a block position including at least one edge memory block at an edge of the memory bank and at least one non-edge memory block. Each memory block includes a plurality of memory cells. Each memory cell associated with at least one bit line and at least one word line. The semiconductor memory device includes a refresh execution circuit configured to activate a less than or equal number of word lines one at a time during a refresh operation for the memory cells in the edge memory block as activated one at a time during a refresh operation for the memory cells in the non-edge memory block.