Memory circuit with redundant configuration

Abstract

A memory circuit has a plurality of blocks which further comprises a plurality of regular sectors and a spare sector, wherein each sector further comprises a plurality of memory cells, and when a regular sector in a first block is defective, this defective regular sector is replaced with a spare sector in a second block. And responding to an address to be supplied, the regular sector corresponding to the supplied address in the first block and the spare selector in the second block are selected simultaneously during a first period, and after the first period, selection of one of the regular sector and the spare sector is maintained according to the result of redundancy judgment on whether the supply address matches with the redundant address. Regardless the result of redundancy judgment on whether the supplied address matches the redundant address indicating the defective sector, a regular sector in the first block and the spare sector in the second block, to be a pair thereof, are set to selected status simultaneously during the first period when access operation stars, so a drop in access speed due to a redundancy judgment operation can be suppressed.