US Patent 7719906 Semiconductor device

Disclosed is a semiconductor storage device in which a cell array including a plurality of cells in need of refresh for data retention includes the redundancy area, which has a plurality of redundant cells for replacing faulty cells of a normal area within the cell array. When the redundancy area is tested, a refresh counter circuit for generating and outputting refresh addresses rearranges the address in such a manner that a row address of the redundancy area is substantially reduced and placed on a lower-order bit side inclusive of the LSB of the counter.