International Business Machines Corporation

Kabushiki Kaisha Toshiba

Toshiba Memory Corporation

Toshiba America Electronic Components, Inc.

Other

Sony Computer Entertainment Inc.

Takaaki Nakazato

Sang Hoo Dhong

Osamu Takahashi

Toru Asano

Atsushi Kawasumi

Yukihiro Fujimoto

Yuki Inuzuka

Hiroshi Yoshihara

A semiconductor storage device includes a memory cell having a first variable resistance element changeable from a first state to a second state at which a resistance value of the first variable resistance element is higher than that of the first variable resistance element at the first state, and a second variable resistance element connected to the first variable resistance element in series and changeable from a third state to a fourth state at which a resistance value of the second variable resistance element is higher than that of the second variable resistance element at the third state. In the memory cell, a first snapback occurs at a first threshold current and a first threshold voltage, and a second snapback occurs at a second threshold current that is greater than the first threshold current and a second threshold voltage that is greater than the first threshold voltage.

Semiconductor storage device and method of reading data therefrom

A semiconductor memory device includes a first conductor that extends in a first direction, a second conductor that extends in a second direction, a first memory cell connected between the first conductor and the second conductor and including a phase change element, and a control circuit. The control circuit applies a first voltage across the first memory cell via the first conductor and the second conductor during a first period of time of a write operation targeted to the first memory cell, and a second voltage across the first memory cell via the first conductor and the second conductor during a second period of time of the write operation after the first period. The first voltage is an overshoot voltage. The second voltage is a preset voltage having a magnitude sufficient to place the phase change element in a molten state during the second period of time.

Semiconductor memory device

A sense amplifier circuit includes first and second lines and first and second inverters. Each inverter includes an input terminal, an output terminal, and a power source terminal. A second signal line potential is supplied to the first inverter input terminal. The second inverter input terminal is connected to the first inverter input terminal. A first signal line potential is supplied to the second inverter input terminal. A first switch transistor is connected to the first inverter power source terminal and has a gate connected to the second signal line. A switch second transistor is connected to the second inverter power source terminal and has a gate connected to the first signal line.

Sense amplifier circuit

Methods and systems for embodiments of a 9T memory cell, memory devices which utilize such 9T memory cells and the creation of embodiments of such memory devices are disclosed. More specifically, an embodiment of a 9T memory cell may comprise a 6T memory cell portion and a 3T read port. Additionally, in one embodiment, a memory which utilizes 9T memory cells may be made by from a grid comprising columns and rows of transistors formed according to a layout for 6T memory cells.

Method and system for semiconductor memory

Methods and apparatus provide for enabling a digital circuit by biasing at least one switch transistor ON such that a voltage potential of a virtual ground node is substantially equal to a voltage potential of a ground node for a power supply to the digital circuit, wherein the digital circuit is implemented using a plurality of transistors in a silicon-on-insulator (SOI) arrangement and at least some of the transistors are referenced to the virtual ground node; and disabling the digital circuit by biasing a gate terminal of the switch transistor below the voltage potential of the ground node.

Methods and apparatus for reducing leakage current in a disabled SOI circuit

A memory system including a memory array with redundant wordlines. The memory system includes a memory wordline tester that determines if any of the wordlines exhibits a defect. The memory system also includes decoder redundancy logic that efficiently couples to wordline shift logic using a reduced number of control signal lines therebetween. The shift logic shifts defective wordlines to upstream wordlines in the array to bypass the defective wordlines.

Method and apparatus for wordline redundancy control of memory in an information handling system

A method, an apparatus, and a computer program are provided to reduce the number of required latches in a deep pipeline wordline (WL) decoder. Traditionally, a signal local clock buffer (LCB) has been responsible for providing a driving signal to a WL driver. However, with this configuration, a large number of latches are utilized. To reduce this latch usage, a number of LCBs are employed, such that one latch can enable an increased number of WLs. Hence, the overall area occupied by latches is reduced and power consumption is reduced.

Apparatus and method of word line decoding for deep pipelined memory

Systems and methods for reducing or eliminating the effect of timing variations in signals generated by devices that are subject to the history effect, wherein devices are enabled using a combination of timing signals, some of which are subject to timing variations arising from the history effect, and some of which are not. In one embodiment, a sense amplifier includes a pair of serially configured transistors that couple the sense amplifier to ground. One of the transistors is switched on/off by a clock signal that is not subject to history-effect timing variations, and the other is switched on/off by a signal that is subject to such variations. The second signal has pulses that are selectively delayed so that they will (or will not) overlap with the pulses of the clock signal in a controlled manner.

Systems and methods for controlling timing in a circuit

Systems and methods for increasing the amount of current that can flow through the data line pull-down transistors in a sense amplifier by tying the bodies of these transistors to a voltage other than ground. In one embodiment, the bodies of the data line pull-down transistors in a sense amplifier are tied to the intermediate nodes on the opposing side of the sense amplifier to increase the current flow through the data line pull-down transistors, and also to reduce the voltage at the intermediate node that will be pulled low by the action of the bit line transistors. In one embodiment, the sense amplifier also includes pre-charge circuits which pre-charge the intermediate nodes to a predetermined voltage that is not reduced by the threshold voltage of the pull-down transistors.

SOI sense amplifier with cross-coupled body terminal

Systems and methods for decreasing the sensitivity of a sense amplifier to variations in the threshold voltages of the data line pull-down transistors by pre-charging the intermediate nodes of the sense amplifier to the voltages on the opposing bit lines when the sense amplifier is not enabled. In one embodiment, the intermediate nodes are coupled to the input bit lines through transistors that are switched on when the sense amplifier is not enabled and switched off when the sense amplifier is enabled. In one embodiment, the intermediate nodes are pre-charged to a predetermined voltage before being pre-charged to the voltages on the bit lines. In one embodiment, the bodies of the data line pull-down transistors may also be body-tied to the opposing intermediate nodes to increase current flow through these transistors, particularly on the side of the sense amplifier that will be pulled low when the sense amplifier is enabled.

SOI sense amplifier with cross-coupled bit line structure

Disclosed is an apparatus for and a method of overcoming signal delay problems in a read-out path occurring in connection with pipelined memory circuits. A latch type sense amplifier (SA) is used to receive the memory cell logic levels during a pre-charge state in a cycle prior to read-out. Thus, the SA may quickly provide an output signal during a read latch clock cycle. The SA output is passed through a dynamically enabled logic circuit to a latch circuit for holding the receiving logic value for use in the next clock cycle.

Latch type sense amplifier method and apparatus

A decoder for use in wordline/bitline redundancy control is disclosed. In one aspect, the decoder includes first and second wordlines respectively coupled to redundant first and second wordlines, where the first and second wordlines are configured to be activated based on decoded first and second addresses. In addition, the decoder includes first and second shift registers respectively coupled to the redundant first and second wordlines, where each is configured to respectively activate the redundant first and second wordlines when the first or second wordlines contain a defect. In addition, a method of selecting wordlines for use in wordline/bitline redundancy control and a wordline decoder having redundancy control capabilities are also disclosed.

Apparatus and method of wordline/bitline redundancy control using shift registers in an SRAM

The present invention provides a subarray control apparatus and method. The subarray control includes a wordline driver configured to generate a wordline activation signal, and a write/read control signal generator configured to generate a write/read enable signal. In addition, the subarray control includes a timing generator configured to generate a wordline timing signal input to the wordline driver and a write/read timing signal input to the write/read control signal generator. The wordline activation signal is based on enable data captured by a first transparent latching circuit and the wordline timing signal generated within the subarray. The write/read enable signal is based on enable data captured by a second transparent latching circuit and the write/read timing signal generated within the subarray. Accessing subarray cells in a memory module and a memory module incorporating the subarray control are also disclosed.

Subarray control and subarray cell access in a memory module

A pulse generator circuit includes a first logic means, a second logic means, a first delay means, and a second delay means. The first logic means is for receiving an input clock signal. The first delay means is for delaying the input clock signal by a first delay time. The second logic means is for receiving a signal output from the first logic means. The second delay means is for delaying the signal output from the first logic means by a second delay time.

Pulse generating circuit

A semiconductor device comprises a first bit line, a second bit line, a memory cell electrically coupled to the first bit line and the second bit line, a first amplification circuit configured to amplify a potential of the first bit line and a second amplification circuit configured to amplify a potential of the second bit line.

Growing community of inventors

Austin, TX, United States of America

Takaaki Nakazato