Fujitsu Corporation

Spansion Llc.

Junya Kawamata

Kenji Arai

Kazuki Yamauchi

Tsutomu Nakai

Hirokazu Nagashima

Kenichi Takehana

Kazuhide Kurosaki

Hideyuki Furukawa

Takaaki Ichikawa

Haruo Shoji

Tomomi Furudate

Yuzuru Matsuno

Tatsuya Yoshimoto

Masato Kitamura

A semiconductor device includes a first nonvolatile storage area including a plurality of sectors, a second nonvolatile storage area, a third nonvolatile storage area located in the first nonvolatile storage area, a fourth nonvolatile storage area located in the second nonvolatile storage area, and a control portion selecting one of a first mode and a second mode. In first mode, sectors where the third nonvolatile storage area is not located in the first nonvolatile storage area are used as a main storage area, and the second nonvolatile storage area is used to store a program or data that is read before the first nonvolatile storage area is accessed, the third nonvolatile storage area being used to store control information that controls writing, reading, and erasing of data involved in the first nonvolatile storage area or the second nonvolatile storage area. In the second mode, the first nonvolatile storage area is used as the main storage area, and the fourth nonvolatile storage area is used to store the control information.

Semiconductor device and method for controlling thereof

A semiconductor device has a plurality of bit lines BL provided in a memory cell area, a plurality of word lines WL provided crossing the plurality of bit lines BL, a plurality of diffusion source lines VSL provided along the plurality of word lines WL, a plurality of non-volatile active cells AC storing data, the plurality of non-volatile active cells AC being provided at cross sections of the plurality of bit lines BL and the plurality of word lines WL and being connected to the plurality of bit lines BL, the plurality of word lines WL, and the plurality of diffusion source lines VSL, and a controller simultaneously writes or reads data to and from at least two active cells AC among the plurality of active cells AC, in which the number of the plurality of active cells AC is less than that of the cross sections.

Semiconductor device and controlling method for the same

Structures, methods, and systems for enhanced erasing operation for non-volatile memory are disclosed. In one embodiment, a semiconductor device which comprises a memory cell array having a plurality of non-volatile memory cells, a negative voltage generating circuit for applying a negative voltage to a word line of the memory cell array during an erasing operation of the memory cell array, and a positive voltage generating circuit for applying a positive voltage to a well of the memory cell array when the negative voltage reaches a predetermined voltage.

Enhanced erasing operation for non-volatile memory

A plurality of memory cells corresponding to an address space larger than 2and smaller than 2, an invalid address detecting circuit, and an invalid signal outputting circuit are comprised. Upon command input, the invalid address detecting circuit invalidates a command in the case where the invalid address detecting circuit detects a fact that an address signal supplied from exterior indicates an invalid address space. Therefore, at the time of invalid address supply, internal circuits are not activated and an erroneous write or erase operation can be prevented. Since the internal circuits do not operate, power consumption can be reduced substantially. The invalid signal outputting circuit outputs an invalid signal by receiving the fact of invalid address signal detection by the invalid address detecting circuit. Therefore, a system unit mounting the semiconductor memory device can easily recognize that the invalid address signal has been supplied to the semiconductor memory device. As a result, a malfunctioning can be prevented and reliability of the system unit improves.

Semiconductor memory device and method of controlling same

A nonvolatile memory circuit, comprises: memory regions, which contain N (N is a plurality) of the sectors, N not being an exponentiated number of two and the sectors having the same capacity; a sector selection circuit for decoding a sector address and selecting the sector which corresponds to the sector address; and a memory control circuit which, in response to an erase command, executes an erase operation to the selected sector and, upon verifying that the erasure is complete, sequentially changes said sector address to select the next sector. When a sector that does not exist in the memory regions is selected, said memory control circuit selects the next sector without performing an erase operation to the nonexistent sector.

Non-volatile memory circuit comprising automatic erase function

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 2 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.

Electronically rewritable non-volatile semiconductor memory device

A nonvolatile semiconductor memory device includes a plurality of banks including respective memory cell arrays independent of each other, a password storage area that is associated with one of the banks, a bank decoder which generates a bank selection signal by decoding a bank address, a first bank selection circuit which outputs a write instruction or a read instruction to the one of the banks, a plurality of second bank selection circuits which outputs a write instruction or a read instruction to the respective banks except for the one of the banks, and a command-decode-&-bank-control circuit which controls the first and second bank selection circuits such that receipt of a first command causes one of the first and second bank selection circuits selected by the bank selection signal to output a write instruction or a read instruction, and such that receipt of a second command causes the first bank selection circuit to output a write instruction independently of the bank selection signal, and causes one of the second bank selection circuits selected by the bank selection signal to output a read instruction.

Nonvolatile semiconductor memory device of dual-operation type with data protection function

A semiconductor memory device is provided. The semiconductor memory device includes a primary memory area including a plurality of memory blocks arranged in rows and columns, the plurality of memory blocks including a predetermined memory block; a secondary memory area including a hidden memory block situated in the same column as the predetermined memory block; a decision circuit selecting one of a first mode for reading first data from the primary memory area and a second mode for reading second data from the secondary memory area, the decision circuit outputting a signal when the second mode and an address of the predetermined memory block are specified; a column decoder selecting a column corresponding to a column address inputted thereto; and a word-line decoder selecting a word line of the hidden memory block by boosting a word line of an adjacent memory block included in the primary memory area in response to the signal, the word-line decoder being included in the adjacent memory block, wherein the second data is read from the hidden memory block when the column decoder and the word-line decoder select the column corresponding to the hidden memory block and the word line of the hidden memory block respectively. According to the present invention, the semiconductor memory device enables efficient selection of an address of the secondary memory area with a simple circuit structure.

Semiconductor memory device utilizing access to memory area located outside main memory area

The present invention is a non-volatile memory comprising: first and second floating gate MOS transistors which are electrically written and erased and which are operatively connected between power sources serially; and an output terminal connected to the contact point of the first and second MOS transistors; wherein a first datum is stored by writing to the first MOS transistor and erasing the second MOS transistor, and a second datum is stored by erasing the first MOS transistor and writing to the second MOS transistor. With the aforementioned memory device, through current does not flow to the power source, because only one transistor will be conductive even if read voltage is applied to the control gate of both transistors. Consequently, reading time can be shortened, without leading to increased power consumption, by maintaining the control gate at the read voltage level.

Growing community of inventors

Kawasaki, Japan

Junya Kawamata