Semiconductor memory device with individual and selective refresh of data storage banks

摘要

A conventional semiconductor memory device may be in need of a special refresh sequence if it is desired to reduce the current consumption in connection with a refresh operation. With this in view, there is disclosed a semiconductor memory device 1 that has a recording area 30 formed by a plurality of memory banks 31 to 3n. The refreshing operation for this semiconductor memory device 1 may be performed on the memory bank basis. The semiconductor memory device 1 includes refresh control circuits 21 to 2n and holding circuits 11 to 1n in association individually with the memory banks 31 to 3n. The holding circuits 11 to 1n are set when data has been written in associated ones of the memory banks 31 to 3n following resetting of the semiconductor memory device. The refresh control circuits 21 to 2n set the associated memory banks 31 to 3n to a refresh enabling state in case the associated holding circuits 11 to 1n are in a set state (FIG. 1).