Abstract: A digital design and technique may be used to implement a Manhattan Nearest Neighbor content addressable memory function by augmenting a serial content addressable memory design with additional memory and counters for bit serially accumulating in parallel and subsequently comparing in parallel all the Manhattan distances between a serially inputted vector and all corresponding vectors resident in the CAM. Other distance measures, besides a Manhattan distance, may optionally be used in conjunction with similar techniques and designs.

Abstract: In a method of operating a nonvolatile memory device, at least one among memory cell blocks of the nonvolatile memory device is designated as a content addressable memory (CAM) block which includes a plurality of CAM cells coupled to respective word lines of the nonvolatile memory device. Chip information for operations of the nonvolatile memory device is stored in the CAM cells which are coupled to a selected word line, whereas the remaining CAM cells of the CAM block are in an erased state.

Abstract: A data processing apparatus is provided having a cache memory comprising a data storage array and a tag array and a cache controller coupled to the cache memory responsive to a cache access request from processing circuitry to perform cache look ups. The cache memory is arranged such that it has a first memory cell group configured to operate in a first voltage domain and a second memory cell group configured to operate in a second voltage domain that is different from the first voltage domain. A corresponding data processing method is also provided.

Abstract: The invention provides a content-addressable memory cell formed by two transistors that are configured so that one of the transistors is for storing a data bit and the other for is storing the complement of the data bit. Each transistor has a back control gate that can be controlled to block the associated transistor. The device also includes a comparison circuit that is configured to operate the first and second transistors in read mode while controlling the back control gate of each of the transistors so as to block the passing transistor if a proposed bit and the stored bit correspond. Then, the presence or absence of current on a source line linked to the source of each of the transistors indicates whether the proposed bit and the stored bit are identical or not. The invention also provides methods for operating the content-addressable memory cells of this invention, as well as content-addressable memories having a plurality of the content-addressable memory cells of this invention.

Abstract: Methods and circuits for CAM cells using PMCs are disclosed herein. In one embodiment, a BCAM cell can include: (i) a first PMC coupled to a first access transistor and a bit node, where the first access transistor is coupled to a true bit line; (ii) a second PMC cell coupled to a second access transistor and the bit node, where the second access transistor is coupled to a complement bit line, and the first and second access transistors are controllable by a word line; (iii) a program enable transistor coupled to the bit node, and configured to couple a program control voltage to the bit node when enabled; and (iv) a match indication transistor configured to discharge a match line in response to states of the true and complement bit lines relative to the bit node.

Abstract: Static-based comparators and methods for comparing data are disclosed. The static-based comparator is configured to selectively switch at least one comparator output in response to a comparison of corresponding data with compare data, and a validity indicator for the data. If the validity indicator indicates valid data, the static-based comparator switches to drive the comparator output indicating either a match or mismatch between corresponding compared data. If the validity indicator indicates invalid data, the static-based comparator provides a mismatch on the comparator output without switching the static-based comparator regardless of whether or not the data matches the compare data. In this manner, the static-based comparator does not dissipate power switching the comparator output for data marked invalid. The static-based comparator can be employed in content addressable memories (CAMs) for comparing one or more bits of tag data to corresponding bit(s) of compare data.

Abstract: An entry including multiple bits of unit cells each storing data bit is coupled to a match line. The match line is supplied with a charging current having a restricted current value smaller than a match line current flowing in a one-bit miss state in one entry, but larger than a match line current flowing in an all-bit match state in one entry. A precharge voltage level of a match line is restricted to a voltage level of half a power supply voltage or smaller. Power consumption in a search cycle of a content addressable memory can be reduced, and a search operation speed can be increased.

Abstract: A semiconductor memory device includes a memory cell block configured to include a plurality of main cells and a plurality of CAM cells, a plurality of page buffers configured to store data to be programmed into the memory cell block, and a Y decoder configured to transfer CAM data to respective page buffers, selected from among the plurality of page buffers, in response to a data determination signal and CAM column addresses whenever the CAM data is inputted in a CAM data input mode.

Abstract: The present invention is directed to reduce array area and power consumption in a content addressable memory. A comparator for performing a match determination and a size determination is provided commonly for plural entries each storing data to be retrieved. Each entry includes data storage cells for storing data and mask cells for storing mask bits. The number of mask cells is smaller than that of the data storage cells. Search data is transmitted to the comparator via a search data bus. One of the entries is selected according to a predetermined rule. The comparator decodes the mask bits, generates a mask instruction signal, and performs match comparison and size comparison between the search data and data to be retrieved which is stored in the selected entry.

Abstract: A method includes activating at least two rows of pure memory cells and reading at least one column of activated the memory cells, the reading generating a binary function of data stored in the activated memory cells.

Abstract: A semiconductor memory device includes a memory array configured to include memory cells for storing input data and Code Address Memory (CAM) cells for storing setting data used to set an operation condition; an operation circuit configured to perform a CAM read operation by supplying a read voltage to the CAM cells, perform a test operation for detecting unstable CAM cells in each of which a difference between a threshold voltage and the read voltage is smaller than a permitted limit, from among the CAM cells, and perform an erase operation or a program operation for the unstable CAM cells; and a controller configured to control the operation circuit so that the program operation for storing the setting data in the unstable CAM cells is performed if the number of unstable CAM cells detected in the test operation is greater than a permitted value.

Abstract: An apparatus comprising a memory array and a plurality of processing circuits. The memory array may be configured to store a plurality of data bits in a plurality of rows and a plurality of columns. A plurality of data words may be stored in a respective plurality of the columns. The plurality of processing circuits may each be configured to compare (i) a test bit of a plurality of bits of an input data word with (ii) a test bit of one of the plurality of columns to determine a match. The compare may occur on a first clock cycle of an input clock signal. Each of the plurality of processing circuits may be configured to power down a respective column of the memory array if the test bit of the input data word does not match the test bit of the column.

Abstract: The addressing circuit of a semiconductor memory device includes a plurality of register units coupled to an input unit and a plurality of memory cell arrays, wherein the plurality of register units are configured to store inputted data in response to register control signals, and a control unit configured to generate the register control signals, using defect information of respective memory cell arrays, to control whether or not the register units store the inputted.

Abstract: According to one embodiment, a semiconductor associative memory device comprises a retrieval block having retrieval word strings arranged in a column direction, each of the retrieval word strings includes memory cells arranged in a row direction between a word input terminal and a word output terminal, each of the memory cells having a first input terminal, a second input terminal, and an output terminal, wherein in each retrieval word string, the second input terminal of one of the memory cells is used as the word input terminal, and each of other memory cells is connected to the output terminal of adjacent memory cell by the second input terminal, wherein the first input terminals of the memory cells in the same column are connected.

Abstract: A content addressable memory (CAM) device includes an array of memory cells arranged in rows and columns; compare circuitry configured to indicate match results of search data presented to each row of the array; and compare circuitry configured to indicate match results of search data presented to each column of the array, thereby resulting in a two-dimensional search capability of the array.

Abstract: Improved memory management is provided according to a Hierarchical Immutable Content Addressable Memory Processor (HICAMP) architecture. In HICAMP, physical memory is organized as two or more physical memory blocks, each physical memory block having a fixed storage capacity. An indication of which of the physical memory blocks is active at any point in time is provided. A memory controller provides a non-duplicating write capability, where data to be written to the physical memory is compared to contents of all active physical memory blocks at the time of writing, to ensure that no two active memory blocks have the same data after completion of the non-duplicating write.

Abstract: The present disclosure concerns a magnetic random access memory-based ternary content addressable memory cell, comprising a first and second magnetic tunnel junction respectively connected to a first and second straps extending on each side of the first and second magnetic tunnel junctions, respectively; a first and second selection transistors, respectively connected to one extremity of the first and second straps; a first and second current lines; and a conductive line electrically connecting in series the first and second magnetic tunnel junctions at their ends opposed to the ones connecting the first and second straps. The cell disclosed herein has smaller size and can be advantageously used in memory devices having a high cell density array.

Abstract: A conditionally precharged content addressable memory (CAM) includes forcing a mismatch on a matchline of the CAM if a data entry in the CAM is invalid. The matchline of the CAM is precharged only if the data entry is valid.

Abstract: According to one disclosed embodiment, a content-addressable memory (CAM) system configured for reduced power consumption includes a sensing circuit utilized to apply a sense voltage to a matchline of the CAM system, a valid bit cell coupled to the matchline, and a power cut-off circuit configured to isolate the sense voltage from the matchline when an invalid validity state is stored in the valid bit cell, thereby reducing power consumption by the CAM system. In one embodiment, the power cut-off circuit isolates the sense voltage from the matchline by decoupling the sensing circuit from a control signal when an invalid validity state is stored in the valid bit cell.

Abstract: A content addressable memory and method of operation uses a memory array having a plurality of rows of stored content addressable memory data and compare circuitry for comparing received comparand data with the stored content addressable memory data. A hit signal and one or more parity bits is provided for each row. Erroneous hit detection circuitry coupled to the memory array for each row generates a row error indicator in response to a comparison between parity of the comparand data and parity of a row that is correlated to the hit signal as qualified by assertion of a hit signal of that row. The erroneous hit detection circuitry uses the row error indicator for each row to provide an output which indicates whether at least one asserted hit signal corresponds to an erroneous hit.

Abstract: A semiconductor memory device and a data transmission system that operate in synchronization with a high speed system clock without using a synchronizing circuit such as a DLL or PLL. A semiconductor memory device that operates in synchronization with a system clock provided from outside, outputs a data strobe signal from a data strobe terminal when a read command is executed, and outputs read data in synchronization with the data strobe signal, is provided with a read preamble register that specifies the length of a read preamble outputted prior to output of the read data. A memory controller gives consideration to system clock frequency and internal delay time of the semiconductor memory device, and by optimally setting the read preamble length, can perform data transmission at high speed and without missing head data even if read data output start timing of the semiconductor memory device varies.

Abstract: In one embodiment of the invention, a memory integrated circuit is provided including an address decoder to selectively access memory cells within a memory array; a mode register with bit storage circuits to store an enable bit and at least one sub-channel select bit; and control logic. The control logic is coupled to a plurality of address signal lines, the address decoder, and the mode register. In response to the enable bit and the at least one sub-channel select bit, the control logic selects one or more of the address signal lines to capture independent address information to support independent sub-channel memory accesses into the memory array. The control logic couples the independent address information into the address decoder.

Abstract: A memory cell includes a storage capacitor, a read line, and a storage transistor, where the storage transistor is connected to the read line and is subject to activation by a charge in the storage capacitor. An in-memory processor includes a memory array which stores data, and an activation unit to activate at least two cells in a column of the memory array at generally the same time, thereby to generate a Boolean function output of the data of the at least two cells, wherein each of the at least two cells includes at least a storage capacitor, a storage transistor and a read line, where the storage transistor is connected to the read line and subject to activation by a charge in the storage capacitor.

Abstract: A multi-wafer CAM cell in which the negative effects of increased travel distance have been substantially reduced is provided. The multi-wafer CAM cell is achieved in the present invention by utilizing three-dimensional integration in which multiple active circuit layers are vertically stack and vertically aligned interconnects are employed to connect a device from one of the stacked layers to another device in another stack layer. By vertically stacking multiple active circuit layers with vertically aligned interconnects, each compare port of the inventive CAM cell can be implemented on a separate layer above or below the primary data storage cell. This allows the multi-wafer CAM structure to be implemented within the same area footprint as a standard Random Access Memory (RAM) cell, minimizing data access and match compare delays.

Abstract: A nonvolatile memory device includes a memory cell array, including a first memory cell group configured to store data and a second memory cell group configured to store operation information, including first and second program start voltages, a page buffer unit, including page buffers each configured to store program data for memory cells or store data read from the memory cells, and a control unit configured to, when a program operation is first performed after power is supplied, count a number of program pulses until a verification operation using a first verification voltage is a pass, compare the counted number and a first number of program pulses, select either the first or second program start voltages according to a result of the comparison, and control the program operation to be performed using the selected program start voltage until the power is off.

Abstract: A content addressable memory device with a plurality of memory cells storing ternary data values of high, low, and don't care. An aspect of the content addressable memory device is the use of first memory elements and second memory elements in the memory cells. The first and second memory elements are electrically coupled in parallel circuit to a match-line. The first memory elements are coupled to first word-lines and the second memory elements are coupled to second word-lines. The first memory elements are configured to store low resistance states if the ternary data value is low and high resistance states if the ternary data value is either high or don't care. The second memory elements are configured to store the low resistance states if the ternary data value is high and the high resistance states if the ternary data value is either low or don't care.

Abstract: A network apparatus comprises a plurality of ports, and a forwarding engine coupled to the plurality of ports. The forwarding engine is configured to transfer data units received via at least some of the plurality of ports to one or more appropriate ports in the plurality of ports. The forwarding engine comprises a content addressable memory (CAM) device to store a plurality of data patterns organized in a plurality of groups, wherein the CAM device is configured to, responsive to input data, output in a single cycle a plurality of match indications corresponding to the plurality of groups. The forwarding engine also comprises a logic device coupled to the CAM device and configured to generate an action value based on the plurality of match indications, wherein the action value indicates an action to be taken by the forwarding engine.

Abstract: A memory system including a content addressable memory (CAM) array and a non-CAM array. The non-CAM array, which may share word lines with the CAM array, stores one or more error detection bits associated with each row of the CAM array. A state machine reads entries of the CAM array and corresponding error detection bits of the non-CAM array during idle cycles of the CAM array. Error detection logic identifies errors in the entries read from CAM array (using the retrieved error detection bits). If these errors are correctable, the error detection logic corrects the entry, and writes the corrected entry back to the CAM array (an updated set of error detection bits are also written to the non-CAM array). If these errors are not correctable, an interrupt is generated, which causes correct data to be retrieved from a shadow copy of the CAM array.

Abstract: A nonvolatile memory apparatus includes: a memory cell array including a plurality of planes and configured to store a plurality of code addressable memory (CAM) data in independent planes. A redundancy cell array is configured to replace the memory cell array and a CAM data read unit is configured to read the plurality of CAM data from the respective planes in parallel, in response to a CAM data read command, and store the read data.

Abstract: NAND architecture non-volatile content addressable (CAM) memory devices and methods are described that allows for high density, low cost CAM devices. In addition, the NAND architecture non-volatile CAM memory operates with reduced power consumption characteristics for low power and portable applications. In one NAND architecture non-volatile CAM memory embodiment a wired NOR match line array is utilized. In another embodiment a NAND match line array is shown. In yet other embodiments, hierarchal addressing, hash addressing, tree search and algorithmic/hardware engine based search is detailed utilizing both conventional NAND architecture non-volatile Flash memory arrays and dedicated NAND architecture CAM arrays utilizing wired NOR and wired NAND match lines.

Abstract: An entry including multiple bits of unit cells each storing data bit is coupled to a match line. The match line is supplied with a charging current having a restricted current value smaller than a match line current flowing in a one-bit miss state in one entry, but larger than a match line current flowing in an all-bit match state in one entry. A precharge voltage level of a match line is restricted to a voltage level of half a power supply voltage or smaller. Power consumption in a search cycle of a content addressable memory can be reduced, and a search operation speed can be increased.

Abstract: Power consumption in a Content Addressable Memory (CAM) circuit is reduced by use of a CAM circuit. According to one embodiment of the CAM circuit, the CAM circuit includes a plurality of match lines and match line restoration circuitry. The match line restoration circuitry is configured to prevent at least one of the match lines from being restored to a pre-evaluation state responsive to corresponding enable information.

Abstract: A platform may comprise a core coherency domain, graphics coherency domain and a non-coherent domain. A graphics acceleration unit (GAU) of the graphics coherency domain may generate data units from an application and the data units may comprise display data units. The GAU may annotate the display data units with an annotation value before flushing the display data units to an on-die cache. The GAU may identify modified display data units among the display data units stored in the on-die cache and issue flush commands to cause flushing of the modified display data units from the on-die cache to a main memory. The display engine of the non-coherent domain may use the modified display data units stored in the main memory to render a display on a display device.

Abstract: A code address memory (CAM) cell memory device comprises a first storage unit comprising a first nonvolatile memory cell configured to output a power source voltage in response to a read voltage, and a second storage unit comprising a second nonvolatile memory cell configured to output a ground voltage in response to the read voltage.

Abstract: A data storage system includes a first circuit board, a plurality of sockets coupled to the first circuit board, an connector coupled to each of the sockets for coupling each of the sockets to external circuitry, and a plurality of memory modules, each memory module disposed within one of the sockets. The memory module includes a circuit board, an integrated circuit device having configurable blocks, DRAM devices that form parallel channels of DRAM memory and flash memory devices that form parallel channels of flash memory. The memory module also includes an interface electrically coupled to the integrated circuit device for coupling input and output between the integrated circuit device and external circuitry.

Abstract: A memory system includes a memory device configured to read control data for operating conditions from a content addressed memory (CAM) block by performing a CAM read operation and to perform a data input/output operation based on the control data and a memory controller configured to store the control data of the memory device and to determine whether the memory device is to perform the CAM read operation by comparing the stored control data with the control data of the memory device when an operating mode of the memory device or the memory controller changes.

Abstract: A system is disclosed that includes a content addressable memory and an input register coupled to the content addressable memory. The input register can store a data word and the content addressable memory determines if the data word exists in the content addressable memory. The system also includes a power control circuit coupled to the content addressable memory for selectively providing power to at least a portion of the content addressable memory. The system includes power control logic coupled to the power control circuit to selectively reduce power to the at least a portion of the content addressable memory when valid data does not exist in the at least a portion of the content addressable memory.

Abstract: An integrated circuit (200) includes a semiconductor memory device (202) operative for determining match between received search data and stored data in a plurality of ternary content addressable memory (TCAM) bitcells (100). The plurality of TCAM bitcells (100) each include bit storage including a pair of memory cells (102-0, 102-1) for holding stored data. The TCAM bitcells (100) also include bit comparison circuitry (104) operative for comparing between the stored data and search data on a search line coupled to the TCAM bitcell, wherein the bit comparison circuitry includes a static logic gate operable to provide a match output signal exclusive of a pulsed input. Match circuitry (205) is coupled to receive the match output signal (108) from the plurality of TCAM bitcells (100) for determining whether a match is present for a given search word.

Abstract: A content addressable memory device with a plurality of memory cells storing ternary data values of high, low, and don't care. An aspect of the content addressable memory device is the use of first memory elements and second memory elements in the memory cells. The first and second memory elements are electrically coupled in parallel circuit to a match-line. The first memory elements are coupled to first word-lines and the second memory elements are coupled to second word-lines. The first memory elements are configured to store low resistance states if the ternary data value is low and high resistance states if the ternary data value is either high or don't care. The second memory elements are configured to store the low resistance states if the ternary data value is high and the high resistance states if the ternary data value is either low or don't care.

Abstract: Memory storage requirements for digital signal processing operations, for example, motion-compensated video scan rate conversion, that produce intermediate output data, which is then used as an input to the operation, are reduced by reordering operations and organizing memory allocations in a special manner to allow intermediate output at a particular execution time, to substantially share the same memory space as the intermediate output of a previous execution time. Such a reduction in the amount of memory required for processing operations advantageously reduces cost and power consumption.

Abstract: Aspects of the disclosure provide a CAM module that can be used independent of a defective entry line. The CAM module can include at least a CAM array having at least X CAM entry lines, and an additional CAM entry line. Each CAM entry line may include a selection line for enabling the CAM entry line for writing and/or reading and an entry output for indicating matching to a search key. Further, the CAM module can include a decoder unit that can decode an address to enable one out of X word-lines, and an encoder unit that can encode X matching outputs to a matching address according to a predetermined priority sequence. Additionally, the CAM module can include a switching unit coupling the CAM array with the decoder unit and the encoder unit.

Abstract: The power consumption of a search engine such as a CAM device is dynamically adjusted to prevent performance degradation and/or damage resulting from overheating. For some embodiments, the CAM device is continuously sampled to generate sampling signals indicating the number of active states and number of compare operations performed during each sampling period. The sampling signals are accumulated to generate an estimated device power profile, which is compared with reference values corresponding to predetermined power levels to generate a dynamic power control signal indicating predicted increases in the device's operating temperature resulting from its power consumption. The dynamic power control signal is then used to selectively reduce the input data rate of the CAM device, thereby reducing power consumption and allowing the device to cool.

Abstract: Resistive memories having a not-and (NAND) structure including a resistive memory cell. The resistive memory cell includes a resistive memory element for storing a resistance value and a memory element access device for controlling access to the resistive memory element. The memory element access device is connected in parallel to the resistive memory element.

Abstract: A multi-chip package includes a plurality of memory chips for performing a content addressable memory (CAM) read operation in response to a command signal for the CAM read operation and an address signal for selecting the memory chips and a controller for outputting the command signal and the address signal to the memory chips and controlling the sequence of the CAM read operations for the memory chips.

Abstract: A content addressable memory (CAM) of a data processing device can operate in a normal mode or a test mode. In the normal mode, the CAM provides a match value in response to determining that a received data value matches one of a plurality of values stored at memory locations of the CAM. In a test mode of operation, a plurality of test signals are applied to the CAM, and the CAM provides a match value in response to assertion of one of the test signals. The match value is applied to a functional module associated with the CAM to determine a test result. Accordingly, the test signals applied to the CAM provide a flexible way to generate match values and apply those values to the functional module during testing of the data processing device.

Abstract: Methods for efficiently managing a ternary content-addressable memory (TCAM) by minimizing movements of TCAM entries include determining a first node and a second node in the TCAM, determining if there is a free TCAM entry between the first node and the second node, and storing the new entry in the free TCAM entry. Upon determining that a free TCAM entry does not exist between the first node and the second node, further determining a chain of nodes and then determining if there is a free TCAM entry in the chain of nodes. Upon determining that there is a free TCAM entry within the chain of nodes, moving the TCAM entries identified as the nodes in the chain of nodes to generate a free node nearest to the new entry and inserting the new entry in the free node. Moving the TCAM entries identified as the nodes in the chain of nodes preserves the order of the nodes.

Abstract: A method may include selectively coupling a result line to a reference node in response to a compare data value being applied to a plurality of compare cell circuits; precharging the result line to the precharge potential by enabling a first precharge path while the compare data value is being applied; and after precharging the result line by enabling the first precharge path, disabling the first precharge path to place it in a high impedance state.

Abstract: A technique is presented for implementing a content addressable memory (CAM) function using traditional memory, where the input data is serially loaded into a serial CAM. Various additions, which allow for predicting the result of a serial CAM access coincident with the completion of serially inputting the data are also presented.

Abstract: A CAM (Content Addressable Memory) cell includes first and second data storage portions storing data, horizontal port write gates for storing data applied through a match line pair in the data storage portions in a data write through a horizontal port, and search/read gates for driving the match lines of the match line pair in accordance with the data stored in the data storage portions in a search operation and in a data read through the horizontal port. The match lines are used as horizontal bit line pair, or signal lines for accessing the horizontal port. As the first and second data storage portions are used, it becomes possible to store ternary data, and accordingly, a write mask function of inhibiting a data write at a destination of data transfer is realized. Further, as the CAM cell is used, an arithmetic/logic operation following a search process can be executed selectively, and high speed data writing/reading becomes possible.

Abstract: An embedded processor system including a flash process semiconductor die and a digital process semiconductor die. The flash process semiconductor die includes i) first cache memory configured to cache information associated with an embedded processor, and ii) a first cache controller configured to control the first cache memory. The digital process semiconductor die includes i) a translator configured to translate the information between the flash process semiconductor die and the digital process semiconductor die, and ii) the embedded processor. The embedded processor is configured to process the information.