Nonvolatile semiconductor memory device with write protect data settings for disabling erase from and write into a block, and erase and re-erase settings for enabling write into and erase from a block

Granted: Dec 7, 1999 Filed: Jun 30, 1997

This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.