Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Panasonic Holdings Corporation

Kyoto Ceramic Kabushiki Kaisha

Masayoshi Nakayama

Kazuyuki Kouno

Reiji Mochida

Takashi Ono

Yuriko Hayata

Junichi Kato

Keita Takahashi

Yasuo Murakuki

Takanori Ueda

Asako Miyoshi

Hoshihide Haruyama

Seiji Yamahira

Takafumi Maruyama

Hitoshi Suwa

Hiroyasu Nagai

Norio Hattori

Akira Sugimoto

Takao Ozeki

Saburo Nagano

Yuriko Ishitobi

Kazunori Koga

Shinichi Hatakeyama

Shinichiro Mizuta

A neural network computation circuit that outputs output data according to a result of a multiply-accumulate operation between input data and connection weight coefficients, the neural network computation circuit includes computation units in each of which a memory element and a transistor are connected in series between data lines, a memory element and a transistor are connected in series between data lines, and gates of the transistors are connected to word lines. The connection weight coefficients are stored into the memory elements. A word line selection circuit places the word lines in a selection state or a non-selection state according to the input data. A determination circuit determines current values flowing in data lines to output output data. A current application circuit has a function of adjusting current values flowing in data lines, and adjusts connection weight coefficients without rewriting the memory elements.

Neural network computation circuit including non-volatile semiconductor memory element

A neural network computation circuit that outputs output data according to a result of a multiply-accumulate operation between input data and connection weight coefficients, the neural network computation circuit includes computation units in each of which a non-volatile semiconductor memory element and a cell transistor are connected in series between data lines, a non-volatile semiconductor memory element and a cell transistor are connected in series between data lines, and gates of the transistors are connected to word lines. The connection weight coefficients are stored into the non-volatile semiconductor memory elements. A word line selection circuit places the word lines in a selection state or a non-selection state according to the input data. A determination circuit determines current values flowing in data lines to output output data.

Connection weight coefficients to be used in a neural network computation are stored in a memory array. A word line drive circuit drives a word line corresponding to input data of a neural network. A column selection circuit connects to a computation circuit bit lines to which a connection weight coefficient to be computed is connected. The computation circuit determines the sum of cell currents flowing in the bit lines. A result of the determination made by the computation circuit is stored in an output holding circuit, and is set as an input of a neural network in the next layer, to the word line drive circuit. A control circuit instructs the word line drive circuit and the column selection circuit to select the word line and the bit line to be used in the neural network computation, based on information held in a network configuration information holding circuit.

Neural network computation circuit including semiconductor memory element, and method of operation

A neural network computation circuit includes in-area multiple-word line selection circuits that are provided in one-to-one correspondence to a plurality of word line areas into which a plurality of word lines included in a memory array are logically divided. Each of the in-area multiple-word line selection circuits sets one or more word lines in a selected state or a non-selected state, and includes a first latch and a second latch provided for each word line.

Neural network computation circuit including semiconductor storage elements

A variable resistance non-volatile memory device includes a memory cell array including memory cells, a write circuit, and a control circuit. Each memory cell includes a memory element that is a non-volatile and variable-resistance memory element, and a cell transistor. The write circuit includes a source line driver circuit connected to the cell transistor and a bit line driver circuit connected to the memory element. When performing a write operation of changing the memory element to a low resistance state, the control circuit performs control for allowing current having a first current value to flow through the memory element, and subsequently performs control for allowing current having a second current value to flow through the memory element. The second current value is greater than the largest value of overshoot current flowing through the memory element after the start of the changing of the memory element to the low resistance state.

Variable resistance non-volatile memory device

A nonvolatile semiconductor storage apparatus is provided. To a data node and a reference node, a first transistor and a second transistor are respectively connected. In a data state determining operation, in the case where voltage is applied to the data node and reference node, the first and second transistors operate as precharge transistors in a first operation mode, and operate as mirror transistors in a second operation mode. The first and second operation modes are switched.

Nonvolatile semiconductor storage apparatus

A memory array includes a plurality of memory cells arranged in a matrix, each memory cell including a cell transistor and a variable resistance element connected to an end of the cell transistor, and a cell transistor performance measuring cell including a MOS transistor. The cell transistor performance measuring cell is used to stabilize resistance values in a low resistance state and a high resistance state of the variable resistance element irrespective of variations in the cell transistor and thereby improve read characteristics and reliability characteristics of a nonvolatile semiconductor storage device.

Nonvolatile semiconductor storage device including cell transistor performance measuring cells

A memory array includes a resistive memory cell array having a first cell transistor and a resistance change element connected in series and a reference cell array having a second cell transistor and a resistance element connected in series. The second cell transistor of the reference cell array is connected to a reference source line, and the resistance element is connected to a reference bit line. A dummy memory cell is connected to the reference bit line in the memory cell array, and both ends of a resistance change element of the dummy memory cell are short-circuited through the reference bit line.

Nonvolatile semiconductor memory device

Bit lines connected to each nonvolatile memory cell are selected by corresponding selective transistors. A first drive circuit for driving the gate of one of the selective transistors receives a voltage selected by a first voltage switch, and a second drive circuit for driving the gate of the other selective transistor receives a voltage selected by a second voltage switch. A transistor constituting the first drive circuit is different in structure from a transistor constituting the second drive circuit.

A main bit line is disposed between a reference main bit line and core main bit lines. A selection transistor disposed between a sub bit line connected to a cell and the main bit line can switch between a conductive state and a non-conductive state independently of other selection transistors. A dummy main bit line can be set to ground potential by a shield grounding section, and can be used as a shield line of the reference main bit line.

Semiconductor memory device

In a non-volatile semiconductor memory device, variations in voltage applied to a bit line when an erase voltage applying step is repeatedly executed are suppressed, thereby reducing variations in Vt after erasure. A memory array includes memory cells arranged in an array, a plurality of word lines, and a plurality of bit lines and main bit lines. The memory array also includes a usable region which can store data and an isolation region which cannot store data. Each bit line provided in the usable region is connected via a select transistor to the corresponding main bit line. At least one main bit line is connected not only to a bit line of the usable region, but also to a bit line of the isolation region via a select transistor.

Non-volatile semiconductor memory device

In a semiconductor memory device, a voltage rise due to IR-DROP is suppressed which occurs when a ground voltage is applied to a memory cell during a program operation. Discharge transistors are provided between the ground and bit lines connected to the source and drain of the memory cell. The discharge transistors receive mutually independent discharge control signals which are generated and outputted from a DS decoder driver at the respective gates thereof. To the bit line which applies the ground voltage to the memory cell, the ground voltage can be set using the discharge transistor.

In order to determine data stored in a memory cell of a resistive cross-point cell array, two reference cells having two different known resistance values (e.g., data '0' and data '1') are provided, and a difference in current between a selected cell and the reference cell having data &#x201c;0&#x201d; and a difference in current between the selected cell and the reference cell having data &#x201c;1&#x201d; are compared. By comparison with a current of the reference cell which has a parasitic current as with the selected cell and has known data &#x201c;0&#x201d;/&#x201c;1&#x201d;, data can be determined while suppressing an influence of a parasitic current.

A memory cell array with a group of memory cells capable of retaining two-bit information. Each memory cell has a pair of transistors having charge storage regions, mutually connected gates, and mutually connected sources. Word lines are provided to the gates of the transistors. Bit lines are provided to the sources and drains of the transistors. A pair of the bit lines respectively connected to the drains of a pair of transistors included in a memory cell are connected to a comparison input terminal of the differential detector. An information retained in the memory cell is read based on a comparison result of current amounts inputted to the differential detector via the pair of bit lines obtained by the differential detector in a state where memory cell currents are simultaneously and independently supplied to the pair of transistors.

A memory cell array is logically divided into a plurality of regions having different reading speeds, the respective regions having the different reading speeds include region information storage regions for storing region information in which at least two addresses present in the memory cell at the same time are set to be different regions, a reading control circuit is constituted to carry out a reading operation by determining any of the divided regions which is to be read, selecting an optimum reading method and controlling the reading circuit based on the region information stored in the region information storage region, and an address which can be read in a short time in multivalued information stored in one memory cell is set to be a high speed reading region and is distinguished from regions having the other reading speeds. Consequently, it is possible to efficiently write and read information of 2 bits or more in one memory cell array without reducing a using efficiency of the memory cell array.

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Kyoto, Japan

Masayoshi Nakayama