During writing of fail addresses to address registers, when writing of a number of fail addresses that is greater than the number of antifuses that have been provided in advance is about to be executed, or when a storage process of a number of fail addresses that is greater than the number of antifuses that have been provided in advance is about to be executed, delivering as output an overflow signal indicating that the writing or storage operation cannot be executed and reporting to the outside that remedy of defects by antifuses is no longer possible.