Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Kunisato Yamaoka

Hiroshige Hirano

Yasuo Murakuki

Masahiko Sakagami

Takashi Miki

Shunichi Iwanari

Yasushi Gohou

Tetsuji Nakakuma

Kazuyo Nishikawa

In-vehicle detection system includes nonvolatile memory, a controller (SoC) that reads and writes data from and in nonvolatile memory, and detector that outputs detection information to SoC. SoC changes a control signal of nonvolatile memory in accordance with the output of detector.

In-vehicle detection system and control method thereof

There are provided a first nonvolatile memory array including a plurality of nonvolatile memory elements which require an erase operation before a write operation, and a second nonvolatile memory array including a plurality of overwritable nonvolatile memory elements. A request to rewrite data is received by a control circuit. The control circuit writes data to be rewritten to the second nonvolatile memory array when the capacity of the data to be rewritten is not more than that of the second nonvolatile memory array.

Semiconductor memory device including two different nonvolatile memories

Provided is a semiconductor memory device compatible with a SRAM and capable of a high-speed data transfer operation while maintaining data reliability. An access to a memory corestarts when an external chip enable signal XCE performs a falling transition. Simultaneously, an external write enable signal XWE and an external address signal ADD are received, and a memory cellin the memory corecorresponding to the received external address signal ADD is selected. When a data read-out from the memory cellor a data write-in to the memory cellis complete, a rewrite timeris activated in accordance with a rising transition of an external chip enable signal XCE or a rising transition of the external write enable signal XWE for performing a data rewrite for the memory cell

Semiconductor memory device

A ferro-electric memory device suppresses deterioration of retention characteristics at the time when an ambient temperature has decreased, without requiring a much longer cycle time. The ferro-electric memory device includes a first ferro-electric capacitor for use in a first normal cell and a second ferro-electric capacitor for use in a second normal cell. The ferro-electric memory device also includes: a temperature detection circuit which detects an ambient temperature of the first and second normal cells; and a normal cell power supply switching circuit which switches a voltage to be applied to the first and second ferro-electric capacitors depending on the detected temperature.

Ferro-electric memory device

In order to omit a reset transistor between a storage node and a cell plate line of a memory cell, a cell plate line is fixed to a potential substantially equal to a ground potential and a bit line is driven with positive and negative voltages.

Semiconductor memory device having a bitline amplified to a positive voltage and a negative voltage

A ferroelectric memory of the present invention comprises: a plurality of normal cells, each of which includes a first ferroelectric capacitor for holding data and a first transistor connected to a first electrode of the first ferroelectric capacitor; a first bit line connected to the first transistor; a first bit line precharge circuit which is a switch circuit provided between the first bit line and a ground; and a word line connected to a gate of the first transistor. The word line is deactivated to disconnect the first ferroelectric capacitor from the first bit line before the first bit line precharge circuit is driven to discharge a potential of the first bit line.

Ferroelectric memory and method for reading data from the ferroelectric memory

Provided is a semiconductor memory device compatible with a SRAM and capable of a high-speed data transfer operation while maintaining data reliability. An access to a memory corestarts when an external chip enable signal XCE performs a falling transition. Simultaneously, an external write enable signal XWE and an external address signal ADD are received, and a memory cell, in the memory core, corresponding to the received external address signal ADD is selected. When a data read-out from the memory cellor a data write-in to the memory cellis complete, a rewrite timeris activated in accordance with a rising transition of an external chip enable signal XCE or a rising transition of the external write enable signal XWE for performing a data rewrite for the memory cell

To provide a semiconductor storage device which can adapt to assembly processes involving different treatment temperatures, can become unrewritable when rewriting of data by the user is prohibited, negates the necessity for developing different semiconductor storage devices, and lowers development cost. A semiconductor storage device is provided with, as areas for storing faulty address information indicating a faulty area and operation mode setting information about the semiconductor storage device, a first setting function storage areaformed from electrically-rewritable nonvolatile memory and a second setting function storage areaformed from once-rewritable nonvolatile memory. Transfer of faulty address information to a faulty address registerand transfer of operation mode setting information to an operation mode registerare selectively performed.

Semiconductor storage device

In a ferro-electric memory including reference cells, if one reference cell is associated with a plurality of normal cells, a period in which 'L' data is written in the reference cell and a period in which 'H' data is written or read out in/from the reference cell are controlled to be shorter than a period in which &#x201c;L&#x201d; data is written in each normal cell and a period in which &#x201c;H&#x201d; data is written or read out in/from each normal cell, respectively. In this manner, stress applied to the reference cell is reduced and, even if writing or reading is repeatedly performed on the normal cells, the reliability of the reference cell is enhanced and deterioration in characteristics of the reference cell due to repetitive rewriting of data is suppressed.

Memory device of ferro-electric

A ferroelectric memory device includes a plurality of bit line pairs, a plurality of sense amplifiers, a plurality of memory cells, a plurality of reference cells, and a control circuit. Each of the bit line pairs is composed of first and second bit lines. Each of the sense amplifiers amplifies a potential difference across the corresponding bit line pair. The memory cells are provided for the respective bit line pairs and each composed of a transistor and a ferroelectric capacitor. The reference cells are provided for the respective bit line pairs and each composed of a transistor and a ferroelectric capacitor. In addition, each of the reference cells on each of the bit line pairs retains data different from data of a reference cell on the adjacent bit line pair. The control circuit drives the sense amplifiers, the memory cells, and the reference cells. During the drive of the sense amplifier, the control circuit inactivates a reference word line connected to the reference cell.

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Osaka, Japan

Kunisato Yamaoka