Flash memory having spare sector with shortened access time

摘要

A semiconductor memory has regular sectors, a spare sector replaced from the regular sectors, and regular sector selection signal generating circuit and a spare sector selection signal generating circuit, which in response to an address change signal generate a regular sector selection signal and a spare sector selection signal. It also has a redundancy memory that stores replacement information read out in response to the address change signal, and a reference redundancy memory read out in response to the address change signal and generating an output signal that changes when this memory information readout is completed. Then, in response to the change in output signal of the reference redundancy memory, either the regular sector selection signal or the spare sector selection signal is set to the deselected state, based on the replacement information.