Sector protection circuit for non-volatile semiconductor memory, sector protection method and non-volatile semiconductor memory

摘要

A sector protection circuit of the invention has a non-volatile storage section storing data indicating sector protection/unprotection for each sector or each sector group, and a volatile storage section storing data indicating sector protection/unprotection for each sector or each sector group. Normally, each sector or sector group can be protected when data indicative of sector or sector group protection is stored in at least one of the non-volatile storage section and the volatile storage section. When a given command is received in the above normal state, data only in the volatile storage section is enabled.