Abstract: A circuit exhibits a signal input, means for determining a reference level on the basis of properties of a signal received at the signal input. In addition, the circuit further exhibits means for evaluating the signal on the basis of the reference level.
Type:
Grant
Filed:
April 5, 2005
Date of Patent:
April 22, 2008
Assignee:
Infineon Technologies AG
Inventors:
Georg Braun, Maksim Kuzmenka, Hermann Ruckerbauer
Abstract: In a semiconductor memory in which redundancy repair is carried out on a block basis, when a defective block of memory cells is replaced by a first redundant block, the adjacent normal block of memory cells closest to the defect, or a part of that normal block, is also replaced by memory cells in a second redundant block. This repair strategy provides a simple way to isolate a defective memory cell so that the defect does not affect non-replaced memory cells.
Abstract: Disclosed herein is a semiconductor memory device for reducing a current consumption used for operating a write command or a read command. The semiconductor memory device includes a global data latch unit for latching a global data loaded on a global data line in response to a first write enable signal to thereby generate a global latch data; a local data write driving unit for receiving the global latch data to output a local data to a local data line in response to a second write enable signal; and a write driver control unit for generating the first write enable signal and the second write enable signal to inactivate the first write enable signal when a write operation is not performed.
Abstract: A memory cell has a selection transistor constituted of an MOS transistor having a gate electrode and a cell transistor constituted of an MOS transistor having the same polarity as the selection transistor, in such a configuration that these two transistors are connected in series. A bit line is connected to a drain region of the selection transistor and a word line is connected to the gate electrode thereof. A gate electrode of the cell transistor is not electrically connected anywhere so as to be in a floating potential state, while a drain region thereof is connected to a source region of the selection transistor. A source line is connected to a source region of the cell transistor.
Abstract: A semiconductor memory device with improved operational performance by reducing the level variation of first and second power voltages applied to a sense amplifier by efficiently locating a decoupling capacitor. The decoupling capacitor is arranged on an empty region of a plurality of the first and second sense amplifiers and connected between the first and second power voltage lines. A plurality of global data I/O line pairs is arranged perpendicular to the direction of a plurality of local data I/O line pairs.
Abstract: In a boosted voltage generating circuit of a semiconductor memory device, an active kicker drive signal generating circuit generates an active kicker drive signal having a first pulse duration in response to a row active command, and generates the active kicker drive signal having a second pulse duration in response to a refresh command. An active kicker circuit is responsive to the active kicker drive signal to generate the boosted voltage. The second pulse duration may be greater than the first pulse duration, which makes it possible to improve the pumping efficiency of the boosted voltage in a refresh operation.
Abstract: A synchronous dynamic random access memory (SDRAM) integrated circuit (IC) configured to receive an external Reset signal for resetting the IC includes an input buffer configured to generate a buffered reset signal RST from the external Reset signal. The SDRAM IC further includes a reset circuit is configured to generate an internal reset signal Reset_En from (a) the RST signal, (b) a clock enable signal CKE which indicates a time when the SDRAM is ready to receive an external command, and (c) a mode register programming signal MRSP which indicates a time when a mode register is to be loaded with data.
Abstract: A static ram cell is described. The cell includes a pair of cross-coupled transistors and a pair of diode-connected transistors operated from a wordline that provides power to the cell. The cell has three main operating modes, reading, writing, and data retention. Reading is performed by sensing current flowing from a powered-up wordline through a conductive one of the cross-coupled transistors. Writing is performed by pulsing the source of the conductive one of the cross-coupled transistors with a positive voltage to flip the conductive states of the cross-coupled transistors. Data retention is performed by using leakage currents to retain the conductive states of the cross-coupled transistors. A decoder for an array of static ram cells may be operated synchronously and in a pipelined fashion using a rotary traveling wave oscillator that provides the clocks for the pipeline. The cell is capable of detecting an alpha particle strike with suitable circuitry.
Abstract: Nonvolatile memory devices support programming and verify operations that improve threshold-voltage distribution within programmed memory cells. This improvement is achieved by reducing a magnitude of the programming voltage steps and increasing a duration of the verify operations once at least one of the plurality of memory cells undergoing programming has been verified as a “passed” memory cell. The nonvolatile memory device includes an array of nonvolatile memory cells and a control circuit, which is electrically coupled to the array of nonvolatile memory cells. The control circuit is configured to perform a plurality of memory programming operations (P) by driving a selected word line in the array with a first stair step sequence of program voltages having first step height (e.g.
Abstract: The present invention presents a scheme for sensing memory cells. Selected memory cells are discharged through their channels to ground and then have a voltage level placed on the traditional source and another voltage level placed on the control gate, and allowing the cell bit line to charge up. The bit line of the memory cell will then charge up until the bit line voltage becomes sufficiently high to shut off any further cell conduction. The rise of the bit line voltage will occur at a rate and to a level dependent upon the data state of the cell, and the cell will then shut off when the bit line reaches a high enough level such that the body effect affected memory cell threshold is reached, at which point the current essentially shuts off. A particular embodiment performs multiple such sensing sub-operations, each with a different control gate voltage, but with multiple states being sensed in each operation by charging the previously discharged cells up through their source.
Abstract: A method and apparatus are provided for high performance, high voltage memory operations on selected memory cells (200) of a semiconductor memory device (100). A high voltage generator (106) during program or erase operations provides a continuous high voltage level (702) on selected word lines (502) and maintains a continuous high voltage level supply to a bit line decoder (120) which sequentially provides the high voltage level (706) to a first portion of bit lines (504) and discharges (708) those bit lines (504) before providing the high voltage level to a second portion (710).
Type:
Grant
Filed:
June 12, 2006
Date of Patent:
March 18, 2008
Assignee:
Spansion LLC
Inventors:
Nian Yang, Boon-Aik Ang, Yonggang Wu, Guowei Wang, Fan Wan Lai
Abstract: A circuit generates a qualified data read strobe signal from a start burst signal and a bidirectional data strobe signal in a DDR memory control module. The circuit includes a delay module that receives the start burst signal and that generates a delayed start burst signal. An enable signal generator receives the delayed start burst signal and generates an enable signal. A first circuit generates the qualified data read strobe signal based on the enable signal and the bidirectional data strobe signal.
Abstract: A method and circuit for controlling an output reference voltage generated by a reference voltage generator disposed on a memory device are provided. A signal for enabling a clocked standby mode of the memory device is received. If the signal indicates that the memory device is in the clocked standby mode, a first reference voltage is generated as the output reference voltage of the reference voltage generator using a first voltage. If the signal indicates that the memory device is not in the clocked standby mode, a second reference voltage is generated as the output reference voltage of the reference voltage generator using a second voltage.
Type:
Grant
Filed:
August 1, 2005
Date of Patent:
March 18, 2008
Assignee:
Infineon Technologies AG
Inventors:
Torsten Partsch, George Alexander, Ben Heilmann, David Herbert
Abstract: A wordline driver circuit can include single stage level shifters to translate a low voltage level (VGND to Vcc) to a high voltage level (Vnwl to Vpp). A wordline driver can further include a two-stage discharge circuit to pull down a wordline from a boosted high voltage Vpp to a boosted low voltage Vnwl. A two-stage discharge circuit can include (i) a first discharge path that can pull the wordline toward a first low voltage VGND; and (ii) a second discharge path that can pull the wordline toward a lower boosted low voltage Vnwl. Initially discharging a wordline to a first low voltage can reduce the amount of charge injected into a boosted low voltage Vnwl supply. A two-stage discharge circuit can be self timed or externally timed.
Type:
Grant
Filed:
September 23, 2005
Date of Patent:
March 18, 2008
Assignee:
Cypress Semiconductor Corporation
Inventors:
David Chapman, Anupam Arora, Lin Ma, Richard Parent
Abstract: A data storage device such as a DRAM memory having a plurality of data storage cells 10 is disclosed. Each data storage cell 10 has a physical parameter which varies with time and represents one of two binary logic states. A selection circuit 16, writing circuits 18 and a refreshing circuit 22 apply input signals to the data storage cells to reverse the variation of the physical parameter with time of at least those cells representing one of the binary logic states by causing a different variation in the physical parameter of cells in one of said states than in the other.
Abstract: Each of a plurality of memory blocks arranged for 1 bit data is divided into two subarrays. A separate local data line is provided for each subarray and coupled to a sense amplifier via an isolation gate. A memory cell is selected in a selected subarray of a selected memory block, and a bit line of the selected memory cell is coupled to a corresponding local data line. Only a local data line of the selected subarray is coupled to the sense amplifier to perform a sense operation, and a global read data line is driven via a read driver in accordance with an output signal of the sense amplifier. A load of a sense node of the sense amplifier in a semiconductor memory device is reduced to implement high-speed reading of internal data.
Abstract: A domino SRAM global bit select circuit provides an interface between dual global read and write bit line pairs to a “local bit select” circuit.
Type:
Grant
Filed:
February 9, 2005
Date of Patent:
February 26, 2008
Assignee:
International Business Machines Corporation
Inventors:
Yuen H. Chan, Ryan T. Freese, Antonio R. Pelella, Arthur D. Tuminaro
Abstract: A refresh control circuit is provide for a pseudo SRAM that includes a plurality of banks. The refresh control circuit includes a buffer enable control unit that outputs a chip select internal control signal, and a bank selection unit that generates a single bank select signal or an all-bank select signal in response to the chip select internal control signal. The single bank select signal is enabled in an active operation to perform a refresh operation on one bank and the all-bank select signal is enabled in a standby operation to perform a refresh operation on all the banks.
Abstract: A semiconductor memory device is provided which comprises a group of address pads and an input circuit configured to receive a first address from the address pads at a first transition of an external clock signal and a second address from the address pads at a second transition of the external clock signal.
Abstract: A semiconductor memory device comprises: a memory cell array having a standard memory cell array part in which dynamic memory cells are arranged in a matrix pattern, and a redundant memory cell array having a redundant memory cell set up to replace a defective memory cell in the standard memory cell array part; an access control part controlling external access operation and refresh access operation regarding the memory cell array; and a redundancy judgment circuit executing redundancy judgment to determine whether the memory cell which is a subject to the external access operation or the refresh access operation is the redundant memory cell or not, controlling so as to access the redundant memory cell, if the subjected memory cell is the redundant memory cell, and controlling so as to access the memory cell in the standard memory cell array, if the subjected memory cell is not the redundant memory cell.