Abstract: A nonvolatile memory device that uses pulsed control and rest periods to mitigate the formation of defect precursors. A first embodiment uses pulsed bitline control, where the coupling between a memory cell channel and a reference voltage is pulsed when it is desired to change state in the associated memory cell. Each pulse may be chosen to be less than about 20 nanoseconds, while a “rest period” between pulses can be on the order of about a hundred nanoseconds or greater. Because bitline control is used, very short rise times can be enabled, enabling generation of pulse durations of 50 nanoseconds or less. In other embodiments, these methods may also be more generally applied to other conductors (e.g., wordline or substrate well, for program or erase operations); segmented wordlines or bitlines may also be used, to minimize RC loading and enable sufficiently short rise times to make pulses robust.

Abstract: A nonvolatile memory device that uses pulsed control and rest periods to mitigate the formation of defect precursors. A first embodiment uses pulsed bitline control, where the coupling between a memory cell channel and a reference voltage is pulsed when it is desired to change state in the associated memory cell. Each pulse may be chosen to be less than about 20 nanoseconds, while a “rest period” between pulses can be on the order of about a hundred nanoseconds or greater. Because bitline control is used, very short rise times can be enabled, enabling generation of pulse durations of 50 nanoseconds or less. In other embodiments, these methods may also be more generally applied to other conductors (e.g., wordline or substrate well, for program or erase operations); segmented wordlines or bitlines may also be used, to minimize RC loading and enable sufficiently short rise times to make pulses robust.

Abstract: A memory storage scheme specially adapted for wear leveling (or other reorganization of logical memory space). Memory space includes a logical memory space of M addressable blocks of data, stored as rows or pages, and N substitute rows or pages. Data is periodically shuffled by copying data from one of the M addressable blocks to a substitute row, with the donating row then becoming part of substitute memory space, available for ensuing wear leveling operations, using a stride address. The disclosed techniques enable equation-based address translation, obviating need for an address translation table. An embodiment performs address translation entirely in hardware, for example, integrated with a memory device to perform wear leveling or data scrambling, in a manner entirely transparent to a memory controller. In addition, the stride address can represent an offset greater than one (e.g., greater than one row) and can be dynamically varied.

Abstract: A ternary content-addressable memory (TCAM) array of cells features reduced area and improved matching functionality. 1T-3R and 2T-3R embodiments are disclosed as illustrative. A row or block of TCAM memory cells may include a serial string interconnecting the cells so as to provide reduced power consumption during matching operations. In other aspects, Pre-charge/Discharge logic configurations are described utilizing complementary resistive ram (cRRAM) storage for input data to form improved programmable logic circuits.

Abstract: Disclosed is a memory including a plurality of resistive change memory cells, including at least a first group and a second group of the memory cells and a comparison circuit configured to conduct a direct relative comparison of a remaining endurance of the first group of memory cells to a remaining endurance of the second group of memory cells.

Abstract: A content addressable memory can include an array of memory cells having multiple memory elements, such as RRAM elements, to store data based on a plurality resistive states. A common switching device, such as a transistor, can electrically couple a plurality of the multiple memory elements with a matchline during read, write, erase, and search operations. In search operations, the memory cells can receive a search word and selectively discharge a voltage level on the matchline based on the data stored by the memory elements and the search word provided to the memory elements. The voltage level of the matchline can indicate whether the search word matched the data stored in the memory cells. The content addressable memory can potentially have an effective memory cell sizing under 0.5F2 depending on the number of layers of memory cells formed over the switching device.

Abstract: A hierarchical memory architecture includes an array of memory sub-arrays, each of which includes an array of memory cells. Each sub-array is supported by local wordlines, local column-select lines, and bitlines. The local wordlines are controlled using main wordlines that extend past multiple sub-arrays in a direction parallel to a first axis, whereas the local column-select lines are controlled using main column-select lines that extend between sub-arrays in a direction perpendicular to the first axis. At the direction of signals presented on the local wordlines and column-select lines, subsets of the bitlines in each sub-array are connected to main data lines that extend over a plurality of the sub-arrays in parallel with the second axis. Some embodiments include redundant data resources that are selected based on a decoding of row addresses.

Abstract: A content addressable memory device based on an extremely compact design, potentially as small as 16F2 per memory cell. One embodiment is based on cells having two memory storage elements, such as RRAM elements. Each RRAM element and a respective FET are connected in series between a common matchline and a respective bitline. Cell content for each cell is matched against a bit of a search word by applying voltages to the respective bitlines dependent upon bit value and causing one of the two RRAM elements for each cell to discharge the matchline over a low resistance path in event of mismatch between the cell content and the bit. If no “quick” discharge occurs for multiple cells of a row, then a match is detected. In addition, a matchline recharge path to a high voltage bitline is substantially eliminated by controlling the FETs with specific wordline voltages.

Abstract: A nonvolatile memory device that uses pulsed control and rest periods to mitigate the formation of defect precursors. A first embodiment uses pulsed bitline control, where the coupling between a memory cell channel and a reference voltage is pulsed when it is desired to change state in the associated memory cell. Each pulse may be chosen to be less than about 20 nanoseconds, while a “rest period” between pulses can be on the order of about a hundred nanoseconds or greater. Because bitline control is used, very short rise times can be enabled, enabling generation of pulse durations of 50 nanoseconds or less. In other embodiments, these methods may also be more generally applied to other conductors (e.g., wordline or substrate well, for program or erase operations); segmented wordlines or bitlines may also be used, to minimize RC loading and enable sufficiently short rise times to make pulses robust.

Abstract: A resistive RAM (RRAM) device has a bit line, a word line, a source line carrying a bias voltage that is a substantially static and non-negative voltage, an RRAM cell, and a bit line control coupled to the bit line circuit. The RRAM cell includes a gate node coupled to the word line, a bias node coupled to the source line, and a bit line node coupled to the bit line. The bit line control circuit is configured to generate non-negative command voltages to perform respective memory operations on the RRAM cell.

Abstract: A content addressable memory can include an array of memory cells having multiple memory elements, such as RRAM elements, to store data based on a plurality resistive states. A common switching device, such as a transistor, can electrically couple a plurality of the multiple memory elements with a matchline during read, write, erase, and search operations. In search operations, the memory cells can receive a search word and selectively discharge a voltage level on the matchline based on the data stored by the memory elements and the search word provided to the memory elements. The voltage level of the matchline can indicate whether the search word matched the data stored in the memory cells. The content addressable memory can potentially have an effective memory cell sizing under 0.5F2 depending on the number of layers of memory cells formed over the switching device.

Abstract: A method of operating a memory device that includes groups of memory cells is presented. The groups include a first group of memory cells. Each one of the groups has a respective physical address and is initially associated with a respective logical address. The device also includes an additional group of memory cells that has a physical address but is not initially associated with a logical address. In the method, a difference in the future endurance between the first group of memory cells and the additional group of memory cells is identified. When the difference in the future endurance between the first group and the additional group exceeds a predetermined threshold difference, the association between the first group and the logical address initially associated with the first group is ended and the additional group is associated with the logical address that was initially associated with the first group.

Abstract: A method of operating a memory device includes receiving first and second sets of bits to be stored in multi-level cells in the device. A multi-level encoding is selected from among a plurality of multi-level encodings for storing the first and second sets of bits in the multi-level cells. Each multi-level encoding includes at least four encoding levels for a respective multi-level cell. Respective multi-level encodings have respective costs associated with programming the first and second sets of bits into the multi-level cells in accordance with the respective multi-level encodings. The multi-level encoding is selected based on the respective costs of the respective encodings. The first and second sets of bits are encoded in accordance with the selected multi-level encoding to produce encoded data for storage in the device such that a respective multi-level cell stores respective bits from both the first and second sets of bits.

Abstract: This disclosure provides a non-volatile memory device that concurrently processes multiple page reads, erases or writes involving the same memory space. The device relies upon a crossbar and a set of page buffers that may each be dynamically assigned to each read or write request. The device also separates memory array control from IO control, such that multiple cycle state change operations can be performed while the buffers are used to transfer data into and out of the buffers along an external data bus; using this structure, the memory device can accept multiple transactions where pages can be immediately loaded into buffers and then “pipelined” either for transfer to a write data register or to an external bus as appropriate. By significantly mitigating the substantial “busy time” associated with program and erase of non-volatile memory devices, especially flash devices, this disclosure greatly expands potential application of such devices.

Abstract: A nonvolatile memory device that uses pulsed control and rest periods to mitigate the formation of defect precursors. A first embodiment uses pulsed bitline control, where the coupling between a memory cell channel and a reference voltage is pulsed when it is desired to change state in the associated memory cell. Each pulse may be chosen to be less than about 20 nanoseconds, while a “rest period” between pulses can be on the order of about a hundred nanoseconds or greater. Because bitline control is used, very short rise times can be enabled, enabling generation of pulse durations of 50 nanoseconds or less. In other embodiments, these methods may also be more generally applied to other conductors (e.g., wordline or substrate well, for program or erase operations); segmented wordlines or bitlines may also be used, to minimize RC loading and enable sufficiently short rise times to make pulses robust.

Abstract: A resistive RAM device includes a bit line, a word line, an RRAM cell coupled to the word line and to the bit line, a write driver and a disable circuit. The write driver is coupled to the bit line. The disable circuit stops a write operation performed by the write driver on a respective RRAM cell when a predefined condition on the bit line is achieved. The predefined condition depends on a mode of operation of the RRAM cell.

Abstract: A resistive change memory device includes a first conductive line, a second conductive line, and a resistive change memory cell that includes a resistive memory element coupled between the first conductive line and the second conductive line. The resistive change memory device also includes control circuitry to apply, via the first conductive line and the second conductive line, a first biasing condition to the resistive change memory cell for a reset operation and a second biasing condition to the resistive change memory cell for a restore operation. The restore operation is performed to counteract a decrease in resistance of the resistive memory element for a reset state of the resistive change memory cell. At least one of a voltage, current, and duration of the second biasing condition is greater than a corresponding voltage, current, or duration of the first biasing condition.

Abstract: Disclosed is a memory including a plurality of resistive change memory cells, including at least a first group and a second group of the memory cells and a comparison circuit configured to conduct a direct relative comparison of a remaining endurance of the first group of memory cells to a remaining endurance of the second group of memory cells.

Abstract: This disclosure provides a multiple-plane flash memory device where high voltage programming (setting) or erasing (resetting) pulses are timed to occur simultaneously. By regulating when each memory plane (e.g., each logical or physical partition of memory having its own dedicated array control and page buffer) applies high voltage pulses, the overhead circuitry needed to control multiple concurrent operations may be reduced, thereby conserving valuable die space. Both the “program phase” and the “verify phase” of each state change operation cycle may be orchestrated across all planes at once, with shared timing and high voltage distribution.

Abstract: This disclosure provides a multiple-plane flash memory device where high voltage programming (setting) or erasing (resetting) pulses are timed to occur simultaneously. By regulating when each memory plane (e.g., each logical or physical partition of memory having its own dedicated array control and page buffer) applies high voltage pulses, the overhead circuitry needed to control multiple concurrent operations may be reduced, thereby conserving valuable die space. Both the “program phase” and the “verify phase” of each state change operation cycle may be orchestrated across all planes at once, with shared timing and high voltage distribution.