Other

Renesas Technology Corp.

Hitachi, Ltd.

Hitachi Ulsi Engineering Corp.

Hitachi Ulsi Systems Co., Ltd.

Floadia Corporation

Renesas Electronics Corporation

Satoshi Noda

Shoji Kubono

Takayuki Kawahara

Katsutaka Kimura

Hiroshi Sato

Keiichi Yoshida

Hiroaki Kotani

Atsushi Nozoe

Koji Shigematsu

Ryotaro Sakurai

Hitoshi Tanaka

Hideaki Kurata

Kenji Kozakai

Yusuke Jono

Yasuhiro Taniguchi

Kosuke Okuyama

Koji Kishi

Kiichi Manita

Masahiro Shimizu

Kazumasa Yanagisawa

Tatsuya Ishii

Yutaka Shinagawa

Shinji Yoshida

Hideo Kasai

Takafumi Kato

Yoshihiro Ikeda

Yasuhiko Kawashima

Fukuo Owada

Toru Matsushita

Takashi Ogino

Tatsuro Toya

Tsutomu Nakajima

Teruo Hatada

Atsushi Tokairin

Tetsuya Muraya

Jiro Kishimoto

Tomoichi Hayashi

Takanori Yamaguchi

A multiply-accumulate operation apparatus is capable of sufficiently restraining a sneak current when employing a precharge method where the magnitude of an electric current flowing through an output line is detected. In a synapse operation section, memory cells storing respective synaptic connection weights are arranged in rows and columns. Output lines are connected to memory cells in the corresponding column, and input lines are connected to memory cells in the corresponding row. Each output line is precharged, and then its electric potential is decreased during the corresponding memory cells flow cell currents corresponding to their synaptic connection weights. A memory element of each memory cell includes a memory transistor, a drain side transistor, and a source side transistor connected in series, and is connected between the corresponding input and output line. The memory transistor stores a synaptic connection weight according to the amount of charge in a charge storage layer.

Multiplier-accumulator

In a semiconductor memory device, voltage application from a memory gate electrode of the memory capacitor to a word line can be blocked by a rectifier element depending on values of voltages applied to the memory gate electrode and the word line without using a conventional control circuit. The configuration eliminates the need to provide a switch transistor and a switch control circuit for turning on and off the switch transistor as in conventional cases, and accordingly achieves downsizing. In the semiconductor memory device, for example, each bit line contact is shared by four anti-fuse memories adjacent to each other and each word line contact is shared by four anti-fuse memories adjacent to each other, thereby achieving downsizing of the entire device as compared to a case in which the bit line contact and the word line contact are individually provided to each anti-fuse memory.

Semiconductor memory device

An electrically programmable and erasable non-volatile semiconductor memory such as a flash memory is designed into a configuration in which, when a cutoff of the power supply occurs in the course of a write or erase operation carried out on a memory cell employed in the non-volatile semiconductor memory, the operation currently being executed is discontinued and a write-back operation is carried out to change a threshold voltage of the memory cell in the reversed direction. In addition, the configuration also allows the number of charge-pump stages in an internal power-supply configuration to be changed in accordance with the level of a power-supply voltage so as to make the write-back operation correctly executable. As a result, no memory cells are put in deplete state even in the event of a power-supply cutoff in the course of a write or erase operation.

Non volatile memory

A nonvolatile memory includes circuits each having first control transistors, memory transistors, second control transistors and memory transistors repeatedly connected in series in sequence. Inversion layers are formed in the direction intersecting the serial direction with turning on of the control transistors. A selection circuit selects a connection of the inversion layer placed under the first control transistor and its corresponding read/write circuit. The control transistors placed on both sides adjacent to the memory transistor are turned on to perform reading. The first control transistors placed on both sides of the second control transistor as viewed from side to side are turned on to perform writing into the other of the right and left memory transistors via one of the right and left memory transistors. The selection circuit connects the read/write circuit and the inversion layer in such a manner that the same read/write circuit is used in reading and writing for the same memory transistor.

Nonvolatile memory

To provide a technique which enables a load on a controller to be reduced by rapidly detecting n-bit errors during writing/erasing on a chip in ECC in a nonvolatile memory. A flash memory of the present invention, which is a nonvolatile memory that includes plural electrically erasable and writable nonvolatile memory cells and performs write-and-verify processing in a write operation on the nonvolatile memory cells, includes an ECC determination circuit that counts the number of bits of write error detected in the write-and-verify processing, and outputs the information, and a status register for holding pass/fail information of the write operation and the information about the number of bits of write error outputted from the ECC determination circuit.

Nonvolatile memory and nonvolatile memory apparatus

The present invention provides a semiconductor memory device capable of preventing a defect caused by falling of a word line and deterioration in patterning precision due to disturbance of the pitch of word lines at an end of a memory block. Plural dummy word lines are disposed at an end of a memory block and a word driver is mounted for the dummy word line to control the threshold voltage of a dummy memory cell formed below the dummy word line. Also at the time of operating a memory area for storing data from the outside, a bias is applied to the dummy word line. The invention can prevent a defect caused by falling of a word line and deterioration in patterning precision due to disturbance of the pitches of word lines at an end of a memory block, and realize high yield and reliable operation.

Semiconductor memory device comprising controllable threshould voltage dummy memory cells

A nonvolatile memory apparatus which need not compare an access address with a faulty address every time for rescuing from any fault is to be provided. The apparatus has memory arrays, data registers for inputting and outputting data to and from the memory arrays, and control circuits. The control circuits, after transferring a plurality of sets of data from the memory arrays to the data registers in response to an instruction to read data, take out rescuing data out of the plurality of sets of data transferred to the data registers, and perform processing to replace with the taken-out rescuing data corresponding faulty addresses on the data register to enable the data on the data register to be supplied to the outside. When any faulty data in the read data are to be replaced with rescuing data on any data register to which data have been transferred from any memory array, read access addresses need not be checked whether or not they are faulty every time an access address is supplied from outside.

Nonvolatile memory apparatus enabling data to be replaced prior to supplying read data and prior to supplying write data

An electrically programmable and erasable nonvolatile semiconductor memory such as a flash memory is designed into a configuration in which, when a cutoff of the power supply occurs in the course of a write or erase operation carried out on a memory cell employed in the non-volatile semiconductor memory, the operation currently being executed is discontinued and a write-back operation is carried out to change a threshold voltage of the memory cell in the reversed direction. In addition, the configuration also allows the number of charge-pump stages in an internal power-supply configuration to be changed in accordance with the level of a power-supply voltage so as to make the write-back operation correctly executable. As a result, no memory cells are put in deplete state even in the event of a power-supply cutoff in the course of a write or erase operation.

A semiconductor memory is designed to avoid a situation that the program cannot escape from a writing operation, and the writing operation can be promptly finished according to the level of an external source voltage. This semiconductor memory has a voltage detecting circuit for detecting whether a boosted voltage has reached a predetermined potential and a timer capable of counting predetermined time. A control circuit applies the boosted voltage to a selected memory cell when the voltage detecting circuit detects that the boosted voltage has reached the predetermined potential or when it is detected that the predetermined time has elapsed since the start of the boosting operation.

Nonvolatile semiconductor memory with controlled supply of boosted voltage

A control of a flash memory includes control for supplying a pulse-shaped voltage to each of non-volatile memory cells until a threshold voltage of the non-volatile memory cell having a first threshold voltage is changed to a second threshold voltage. The control involves a first write mode (coarse write) in which the amount of change in threshold voltage of each non-volatile memory cell, which is varied each time the pulse-shaped voltage is applied, is relatively rendered high, and a second write mode (high-accuracy write) in which the amount of change in threshold voltage thereof is relatively rendered low. As compared with the high-accuracy mode, the number of pulses required to change the threshold voltage of each memory cell is smaller than that in the coarse write mode. Therefore, the number of verify operations at the time that the coarse write mode is used, is small and hence the entire write operation can be speeded up.

Semiconductor integrated circuit and data processing system

For a semiconductor integrated circuit having an internal booster circuit such as a flash memory, voltage booster circuits capable of generating a boosted voltage 10 times or more as high as a relatively low source voltage is to be realized. Charge pumps for carrying out first stage voltage boosting on the basis of a source voltage are configured of parallel capacity type units, and charge pumps for carrying out second stage voltage boosting on the basis of the boosted voltage generated by the first charge pumps are configured of serial capacity type units.

Semiconductor integrated circuit and nonvolatile semiconductor memory

Growing community of inventors

Ome, Japan

Satoshi Noda