Abstract: A method of performing a self refresh of memory cells in a memory device. The memory device includes a first group of cell blocks and a second group of cell blocks and each cell block of the first group shares at least one sense amplifier with a cell block of the second group. The method includes simultaneously activating each cell block of the first group. While the cell blocks of the first group are activated, each memory cell in the first group is refreshed. The method further includes simultaneously activating each cell block of the second group. While the cell blocks of the second group are activated each memory cell in the second group is refreshed.

Abstract: A dynamic random access memory (DRAM) cell structure (and method for making a DRAM cell structure) that is more suitable than current DRAM structures for implementation in ever decreasing semiconductor fabrication geometries. The DRAM cell structure comprises a deep trench (DT) capacitor formed in a substrate. A recess is formed in the substrate proximate the deep trench capacitor. A gate is formed that extends into the recess but does not completely occupy the recess. A source is formed in the substrate in a region beneath the recess. A drain is formed in the substrate in a region laterally and vertically offset from the source. A channel between the source and drain is created beneath the gate along a side wall of the recess. Thus, the depth of the recess determines the length of the channel region. With this DRAM cell structure, it is easier to avoid the high doping concentration issue and the short channel effect.

Abstract: A data bus structure for a dynamic random access memory (DRAM) according to the present invention includes a series of data buses, each shared by a plurality of memory banks, and a switching device to selectively couple the data buses to a global data bus to enable the memory device to provide and receive data. The data bus structure conserves space on a chip or die and prevents significant timing skews for data accessed from different memory banks.

Abstract: A bit line sensing scheme is provided for a semiconductor memory device that significantly reduces current drain during a self-refresh mode. After bit line sensing of a selected wordline and deactivation of the selected wordline, a capacitor is connected to a source node associated with a bit line sensing amplifier for the selected wordline to charge the capacitor with charge remaining on the bit line. Then, during the next activate-precharge cycle for another selected wordline, the capacitor is coupled to the source node of a bit line sensing amplifier associated with another selected wordline to discharge charge stored by the capacitor to the bit line associated with said other selected wordline. Thus, charge is returned from the bit line to the capacitor. This is where the self-refresh current reduction is achieved.

Abstract: Embodiments of the invention provide a method of performing a self refresh of memory cells in a memory device. In one embodiment, the memory device includes a first group of cell blocks and a second group of cell blocks and each cell block of the first group shares at least one sense amplifier with a cell block of the second group. The method includes simultaneously activating each cell block of the first group. While the cell blocks of the first group are activated, each memory cell in the first group is refreshed. The method further includes simultaneously activating each cell block of the second group. While the cell blocks of the second group are activated each memory cell in the second group is refreshed.

Abstract: A bit line sensing scheme is provided for a semiconductor memory device that significantly reduces current drain during a self-refresh mode. After bit line sensing of a selected wordline and deactivation of the selected wordline, a capacitor is connected to a source node associated with a bit line sensing amplifier for the selected wordline to charge the capacitor with charge remaining on the bit line. Then, during the next activate-precharge cycle for another selected wordline, the capacitor is coupled to the source node of a bit line sensing amplifier associated with another selected wordline to discharge charge stored by the capacitor to the bit line associated with said other selected wordline. Thus, charge is returned from the bit line to the capacitor. This is where the self-refresh current reduction is achieved.

Abstract: Twin-cell bit line sensing structures and techniques are provided. Utilizing a folded bit line like structure, with bit line and complementary bit lines located together, sense amplifiers can be between cell arrays. Bit line switches, responsive to activated word lines in an array, may be used to selectively couple bit line pairs of the shared arrays with the sense amplifiers with a single word line activation.

Abstract: A system and method for internal error checking a semiconductor memory device in a much more area and energy efficient manner. According to the method, a predefined data pattern is written to a plurality of memory cells in the memory device. A pause or waiting time interval is initiated after the predefined data pattern is written to the plurality of memory cells. The time interval is based on temperature conditions of the memory device. After the time interval expires, the contents are read from the plurality of memory cells and a parity check operation is performed on said contents to detect any single bit error based on the predefined data pattern written to the plurality of memory cells. The circuitry required for this error checking technique is minimal, and comprises a register, a parity check circuit and a control circuit.

Abstract: A bit line sensing scheme is provided for a semiconductor memory device that significantly reduces current drain during a self-refresh mode. After bit line sensing of a selected wordline and deactivation of the selected wordline, a capacitor is connected to a source node associated with a bit line sensing amplifier for the selected wordline to charge the capacitor with charge remaining on the bit line. Then, during the next activate-precharge cycle for another selected wordline, the capacitor is coupled to the source node of a bit line sensing amplifier associated with another selected wordline to discharge charge stored by the capacitor to the bit line associated with said other selected wordline. Thus, charge is returned from the bit line to the capacitor. This is where the self-refresh current reduction is achieved.

Abstract: A clock stop detector for a memory comprises a first switch that closes in response to a first logic level of a clock signal to charge a capacitor, a second switch that closes in response to a second logic level of the clock signal to discharge the capacitor, and a logic circuit that outputs a control signal based on an inverted clock signal and a charge on the capacitor.

Abstract: A dynamic random access memory device is capable of converting from a full density memory device to a reduced density memory device. The reduced density memory device compensates for cell failures in a plurality of cell blocks, regardless of the location of the cell failures. The memory device includes a row address mapping fuse for selectively determining row address combinations capable of storing data bits. A row address mapping logic is coupled to the row address mapping fuse and is capable of routing data bits to the address combinations capable of storing data bits.

Abstract: A clock stop detector for a memory comprises a first switch that closes in response to a first logic level of a clock signal to charge a capacitor, a second switch that closes in response to a second logic level of the clock signal to discharge the capacitor, and a logic circuit that outputs a control signal based on an inverted clock signal and a charge on the capacitor.

Abstract: A circuit including a deskew circuit. The deskew circuit is configured to receive a first signal having a first edge delayed from a second edge of a second signal by a first delay and a third edge delayed from a fourth edge of the second signal by a second delay. The deskew circuit is configured to provide a third signal having a first deskewed edge delayed from the first edge by a third delay and a second deskewed edge delayed from the third edge by a fourth delay. The difference between the fourth delay and the third delay is substantially equal to the difference between the first delay and the second delay.

Abstract: A dynamic random access memory (DRAM) cell structure (and method for making a DRAM cell structure) that is more suitable than current DRAM structures for implementation in ever decreasing semiconductor fabrication geometries. The DRAM cell structure comprises a deep trench (DT) capacitor formed in a substrate. A recess is formed in the substrate proximate the deep trench capacitor. A gate is formed that extends into the recess but does not completely occupy the recess. A source is formed in the substrate in a region beneath the recess. A drain is formed in the substrate in a region laterally and vertically offset from the source. A channel between the source and drain is created beneath the gate along a side wall of the recess. Thus, the depth of the recess determines the length of the channel region. With this DRAM cell structure, it is easier to avoid the high doping concentration issue and the short channel effect.

Abstract: Twin-cell bit line sensing structures and techniques are provided. Utilizing a folded bit line like structure, with bit line and complementary bit lines located together, sense amplifiers can be between cell arrays. Bit line switches, responsive to activated word lines in an array, may be used to selectively couple bit line pairs of the shared arrays with the sense amplifiers with a single word line activation.

Abstract: Methods and circuits for minimizing or eliminating the effect of trimming circuits in a voltage generating circuit are provided. In general, the effects of channel resistance of switches of the trimming circuit are reduced by utilizing switches in series with the output, rather than in parallel with resistors, as in conventional trimming circuits. Because the switches are not in parallel with the resistors, when the switches are turned on, no channel resistance is added to the effective resistance controlled by the trimming circuit.

Abstract: A clock stop detector for a memory comprises a first switch that closes in response to a first logic level of a clock signal to charge a capacitor, a second switch that closes in response to a second logic level of the clock signal to discharge the capacitor, and a logic circuit that outputs a control signal based on an inverted clock signal and a charge on the capacitor.

Abstract: The present invention relates to a memory cell having a quasi-folded bit line sensing arrangement with an open bit line cell array. The memory cell array noise is negligible compared to the conventional open bit line. Also, the twisted bit line structure can be applied for the invention to reduce the inter-bit line coupling noise. The embodiments of the present invention reduce the size of the edge array, reduce the sensing power requirements, and provide a simple bit line layout. According to one embodiment of the present invention, a memory device comprises a plurality of sense amplifiers, each sense amplifier enabling access to data associated with arrays of cells; a bit line pair being coupled to each sense amplifier and comprising a bit line and a complementary bit line; a plurality of word lines associated with an array of cells; and a plurality of switches is employed to enable access to memory cells of the memory device.

Abstract: A circuit to operate a semiconductor integrated circuit memory device having memory cells in a deep power down mode. The power down circuit includes a transistor switch connected between an external voltage source and the device memory cells and peripheral circuits, a generator for providing a control voltage of a first level different from the value of the external voltage, and a multiplexer that receives as one input the control voltage and as a second input the external voltage. The multiplexer has a selected output of one of the control voltage and external voltage that is applied to a control electrode of the transistor switch. When deep power down mode operation is required, the multiplexer responds to a power down control flag signal to apply the external voltage to the transistor control electrode to turn off the transistor and block application of the external voltage to the memory cells and peripheral circuits.

Abstract: Methods and circuits for minimizing or eliminating the effect of trimming circuits in a voltage generating circuit are provided. In general, the effects of channel resistance of switches of the trimming circuit are reduced by utilizing switches in series with the output, rather than in parallel with resistors, as in conventional trimming circuits. Because the switches are not in parallel with the resistors, when the switches are turned on, no channel resistance is added to the effective resistance controlled by the trimming circuit.