Electronically rewritable non-volatile semiconductor memory device
AssigneeFujitsu Limited
InventorJunya Kawamata
Life of this patent
Estimating the term…
Abstract
The present invention provides a non-volatile semiconductor memory device that can protect each block without increasing a memory element area, and make an access to the memory cells in hidden blocks in a hidden mode in which the hidden blocks are accessed. This electrically rewritable non-volatile semiconductor memory device includes K non-volatile memory elements that store protection information, a non-volatile memory element that stores a protection status, and a storage area that is logically divided into 2K or less blocks. In accordance with information stored in the K non-volatile memory elements and the non-volatile memory element that stored the protection status, a write operation is inhibited in the successive bocks in storage area.
Claims10
A non-volatile semiconductor memory device that is electrically rewritable, comprising:
- K non-volatile memory elements that store protection information;
- a non-volatile memory element that stores information concerning a protection status;
- and
- a storage area that is logically divided into 2K or less blocks,
- wherein a write operation on successive blocks in the storage area is inhibited in accordance with the protection information stored in the K non-volatile memory elements and the information concerning the protection status stored in the non-volatile memory element.
A non-volatile semiconductor memory device that is electrically rewritable, comprising:
- K non-volatile memory elements that store protection information;
- and
- a storage area that is logically divided into 2K or less blocks,
- wherein successive blocks are released from a write inhibited state in the storage area, in accordance with the protection information stored in the K non-volatile memory elements.
The non-volatile semiconductor memory device as claimed in claim l, wherein the storage area constitutes a storage area other than a main storage area.
Dependencies are inferred from the claim text.