Abstract: A memory device for performing logical operations on two or more input variables includes a match line and first and second memory cells. The first and second memory cells collectively include a first, second, third and fourth memory element. The first, second, third and fourth memory elements may have either a first value or a second value programmed therein and wherein the first, second, third and fourth memory elements are programmed to either the high or low resistive values based on a particular logic function to be performed.

Abstract: A content-addressable random access memory having magnetic tunnel junction-based memory cells and methods for making and using same. The magnetic tunnel junction has first and second magnetic layers and can act as a data store and a data sense. Within each cell, registered data is written by setting a magnetic orientation of the first magnetic layer in the magnetic tunnel junction via current pulses in one or more current lines. Input data for comparison with the registered data can be similarly set through the magnetic orientation of the second magnetic layer via the current lines. The data sense is performed by measuring cell resistance, which depends upon the relative magnetic orientation of the magnetic layers. Since data storage, data input, and data sense are integrated into one cell, the memory combines higher densities with non-volatility. The memory can support high speed, reduced power consumption, and data masking.

Abstract: A scheme for ultra-low power content addressable memory based on a ripple search is disclosed. In one embodiment, a system for content addressable memory (CAM), includes a storage unit for storing a portion of content data, and a match module for comparing the portion of the content data with a respective portion of search data received by the match module. The match module includes a first static logic gate associated with a first half of the storage unit storing a sub-portion of the portion of the content data, and a second static logic gate associated with a second half of the storage unit. The first static logic gate forwards a signal for disabling the second static logic gate if the sub-portion of the portion of the content data does not match with a respective sub-portion of the portion of the search data.

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: 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: A semiconductor device includes a CAM cell array that stores the operation setting information as to the semiconductor device, a controller that controls read and write of the CAM cell array, a row decoder, and a column decoder. With this structure, different row addresses are allocated to respective functions of the operation setting information. Accordingly, stress is not caused in the CAM cell array of the unselected functions at the time of programming.

Abstract: A read operation and a search operation are performed during the same cycle within a CAM system including a CAM array by: (1) forcing a non-matching condition to exist in the row of the CAM array selected for the read operation, (2) comparing the read data value with the search data value outside of the CAM array to determine whether a match exists, and (3) prioritizing the results of the search operation performed within the CAM array and the results of the comparison performed outside of the CAM array to provide a final search result.

Abstract: A content addressable memory using encoded data words and search words, and techniques for operating such device. In one embodiment, the data word is transformed into a code word guaranteeing a mismatch of at least two code word bits of different binary values during the memory search operation when the data word does not match a search word. In another embodiment, the search word is transformed into a search code such that the Hamming distance between the code word and the search code is greater than a given threshold when there is a mismatch of at least one bit between the data word and the search word.

Abstract: The range-specified IP addresses are effectively stored to reduce the number of necessary entries thereby the memory capacity of TCAM is improved. The representative means of the present invention is that: the storage information (entry) and the input information (comparison information or search key) are the common block code such that any bit must be the logical value ‘1’; Match-lines are hierarchically structured and memory cells are arranged at the intersecting points of a plurality of sub-match lines and a plurality of search lines; Further the sub-match lines are connected to main-match lines through the sub-match detectors, respectively and main-match detectors are arranged on the main-match lines.

Abstract: A content addressable memory (CAM) device includes a CAM array, a programmable interconnect structure, and a priority encoder. The CAM array includes a plurality of CAM rows, each row including a number of CAM cells for storing a data word and coupled to a match line that indicates a match result for the CAM row. The programmable interconnect structure is coupled to each CAM row and a plurality of CAM rows, each row including a number of CAM cells for storing a data word and coupled to a match line that indicates match results for the row. The programmable interconnect structure coupled to each CAM row, and is configured to logically connect any number N of selected CAM rows together to form a data word chain spanning N rows, regardless of whether the selected CAM rows are contiguous.

Abstract: A content addressable memory (CAM) device includes a plurality of CAM rows, a number of sequencing logic circuits, and a programmable interconnect structure. Each CAM row includes a number of CAM cells to generate a match signal on a match line and includes an enable input. Each sequencing logic circuit includes an input and an output, and is configured to count sequences of match signals from the CAM rows. The programmable interconnect structure selectively connects the match line of any CAM row to the input of any sequencing logic circuit, and selectively connects the output of any sequencing logic circuit to the enable input of any CAM row.

Abstract: 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. Another embodiment shows a content addressable memory (CAM) unit without any in-cell comparator circuitry.

Abstract: A counter circuit is configured to simultaneously maintain individual character match count values for a plurality of overlapping substrings of an input string of characters that match a portion of a regular expression stored in a plurality of rows of content addressable memory (CAM) cells of a ternary CAM device. The counter circuit is selectable between a normal operational mode in which all matching portions of the input string are identified, and a minimum match length operational mode in which only matching portions of the input string that have at least a specified minimum number of characters are identified.

Abstract: A content addressable memory device with a plurality of memory cells storing data words. Each data bit in the data words is set to one of three values of a first binary value, a second binary value, and a don't care value. An aspect of the content addressable memory device is the use of a single memory element and an access device in the memory cells. The memory cells are arranged such that each memory cell is electrically coupled to a single bit line, a single match line, and a single word line. The memory elements in the memory cells store low resistance states if the data bit value is the first binary value, high resistance states if the data bit value is the second binary value, and very high resistance states if the data bit value is the don't care value.

Abstract: Various embodiments of the present invention are generally directed to an apparatus and associated method for handling defective bits in a multi-layer integrated memory device. In accordance with some embodiments, the multi-layer integrated memory device is formed from a plurality of vertically stacked semiconductor layers each having a number of storage sub-arrays and redundant sub-arrays. Each semiconductor layer is tested to determine a defect rate for each array, and a defective portion of a first semiconductor layer having a relatively higher defect rate is stored to a redundant sub-array of a second semiconductor layer having a relatively lower defect rate.

Abstract: An N-way mode CAM (content addressable memory) array includes M rows that each contain N subwords. Each of the N subwords has a respective mode cell. Additionally, a mode input bus is coupled to each mode cell of each of the N subwords, and a data input bus is coupled to each of the M rows. The mode input bus and the data input bus can uniquely identify as a match a single subword or a plurality of subwords in one of the M rows during a search operation. The N-way mode CAM further includes a row address encoder/generator coupled to each of the M rows, and an address output bus coupled to each of the row address encoder/generators. The mode input bus is also coupled to each of the row address encoder/generators. A uniquely identified single subword address may be outputted on the address output bus.

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 CAM device includes a CAM array coupled to a programmable priority encoding (PPE) logic circuit. The CAM array concurrently compares multiple input data with stored data to generate corresponding match results that are provided to the PPE logic circuit. The PPE logic circuit selectively favors the match results of a selected flow over the match results of the other flows in response to a flow select signal, which can be toggled to alternately select the match results of various flows. In this manner, the match results of the selected flow are generated and output even if the HPM index of the selected flow is of a lower priority than those of the non-selected flows, thereby ensuring an even distribution of match results reporting between different flows.

Abstract: A multi-chip memory device includes a number of chips and a control circuit included in each of the chips and configured to generate an internal chip enable signal in response to set data stored therein and an external chip enable signal

Abstract: A built-in self-test system applied to NAND flash memory comprises a built-in self-test circuit, a built-in redundancy-analysis circuit, a content addressable memory, a spare memory, a page-mode processor and an address generator. The built-in self-test circuit is configured to test for defective data in a NAND flash memory. The built-in redundancy-analysis circuit is connected to the built-in self-test circuit. The content addressable memory is connected to the built-in redundancy-analysis circuit for storing the address of the defective data. The spare memory is electrically connected to the content addressable memory. The page-mode processor is configured to generate a page address signal and a compensation signal according to an address signal of the NAND flash memory. The address generator is configured to generate a current address signal according to the page address signal and compensation signal to the content addressable memory.

Abstract: In a method for detecting patterns, a plurality of data patterns is stored in a memory, and a data block from a stream of data is received. A first subset of the data block is compared in parallel to the plurality of data patterns. A second subset of the data block is compared in parallel to the plurality of data patterns, wherein the second subset partially overlaps the first subset. At least one signal is generated that indicates a detected data pattern in the data block.

Abstract: A content addressable memory (CAM) device can include a number of match lines, each coupled to a plurality of CAM cells. The CAM device also includes one or more one precharge circuits. Such a precharge circuit can have a first precharge path that couples a match line to a precharge voltage node in response the activation of a first control signal, and a second precharge path that couples the match line to the precharge voltage node in response to the activation of a second control signal. Prior to a compare operation leakage current through the CAM cells can prevented by disabling the precharge paths and isolating the CAM cells from a reference voltage (e.g., ground). The second control signal can be activated after the first control signal in a compare operation.

Abstract: Systems, devices, and methods, including executable instructions are provided for content addressable memory (CAM). One method includes defining the CAM into an array of data words having M rows and N columns, with each of N and M being greater than one. The data words of the CAM are arranged according to a 2-dimensional priority scheme. Data words outside a selected 1×M column are masked to be ignored in determining a match, and the CAM is searched. Each search includes N compare cycles and each compare cycle having a different 1×M column selected. A highest priority match per compare cycle is pipelined from a priority encoder with the pipelined matches arranged to communicate a priority order in a first dimension of the 2-dimensional priority scheme.

Abstract: A content addressable memory (CAM) device includes a comparand register, a CAM array, and partition logic. The comparand register has inputs to receive a search key, and outputs coupled to the CAM array, which includes a plurality of individually selectable sub-arrays. Each sub-array includes a number of rows of CAM cells and a control circuit, wherein each row of CAM cells is coupled to a match line, and wherein the control circuit has an input to receive a corresponding sub-array enable signal. The partition logic has an input to receive a partition select signal, and is configured to generate the sub-array enable signals in response to the partition select signal. The control circuits selectively propagate the search key through the sub-arrays in response to the sub-array enable signals.

Abstract: A Code Address Memory (CAM) cell circuit of a nonvolatile memory device includes a CAM cell unit configured to store data, a control circuit unit configured to read data stored in the CAM cell unit and to output data read as read data, and register units each configured to comprise a number of registers for storing the read data. Each of the registers is reset such that first data are latched when a reset operation is performed, and is configured to maintain the first data or newly latch second data in response to the read data.

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 Code Address Memory (CAM) cell read control circuit of a semiconductor memory device includes a CAM cell read circuit configured to read data stored in a CAM cell and to output the read data, an internal delay circuit configured to delay an externally input reset signal and to generate a number of internal command signals, and a signal generation unit configured to generate an internal ready/busy signal in response to the internal command signals. The internal ready/busy signal is generated after the externally input reset signal has reset the CAM cell read circuit.

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: A package apparatus includes at least one memory chip, a voltage detection circuit configured to make a determination of whether a voltage supplied to the memory chip is a specific voltage or higher, and a controller configured to control an operation of the memory chip based on a result of the determination.

Abstract: A content addressable memory device (100) and method can have CAM blocks (102-0 to 102-29) organized in block sections (104-0 to 104-6). In an overlay mode of operation, an overlay engine (106) can access an algorithmic search (SPEAR) CAM (102-28 and 102-29) to generate overlay data set search keys (keyFIB<0> and <1>). Multiple data sets (e.g., FIB0, FIB1, ACL0) can be accommodated on the same CAM device by search key multiplexers (108-0 to 108-6) that selectively apply any of a number of data set search keys (keyACL<0>, keyFIB<0> and keyFIB<1>).

Abstract: A distributed, hierarchically-structured, programmable priority encoder for a content addressable memory (CAM) device including at least one section, the section further including a section level priority encoder, and a plurality of blocks, each block further including a block level priority encoder, and a plurality of slices. The distributed, hierarchically-structured, programmable priority encoder, wherein each slice further including a CAM slice, a maskable comparand register coupled to the CAM slice and a programmable priority encoder coupled to said CAM slice and further coupled to said block level priority encoder.

Abstract: A content addressable memory (CAM) device includes a plurality of CAM rows, a number of sequencing logic circuits, and a programmable interconnect structure. Each CAM row includes a number of CAM cells to generate a match signal on a match line and includes an enable input. Each sequencing logic circuit includes an input and an output, and is configured to count sequences of match signals from the CAM rows. The programmable interconnect structure selectively connects the match line of any CAM row to the input of any sequencing logic circuit, and selectively connects the output of any sequencing logic circuit to the enable input of any CAM row.

Abstract: A pre-decoded address is generated at a high speed in a semiconductor memory device. The device comprises a pre-decoder (210) for generating a first pre-decoded address (PDA1) by pre-decoding the input address (ADD), a CAM circuit (220) for activating the match signal (MT) by responding to the indication of a defective memory cell by the input address (ADD), a ROM circuit (230) for outputting a second pre-decoded address (PDA2) and an enable signal (ES) in response to the activation of the match signal (MT), and a multiplexer (240) for selecting either the first or second pre-decoded address (PDA1 or PDA2) on the basis of the enable signal (ES). According to the present invention, there is no need to use a circuit with numerous stages as there is in substituted logic; accordingly, pre-decoded addresses can be generated at a high speed.

Abstract: A column of ternary content addressable memory (TCAM) cells includes a bit line pair that is twisted at a location at or near the center of the column. Data is written to (and read from) TCAM cells located above the twist location with a first bit line polarity. Data is written to (and read from) TCAM cells located below the twist location with a second bit line polarity, opposite the first bit line polarity. As a result, read leakage currents introduced by TCAM cells storing ‘Don't Care’ values are reduced.

Abstract: A search engine device includes a lookup circuit, such as a content addressable memory (CAM) array. This lookup circuit is configured to generate multiple active match signals in response to detecting multiple matches between a search operand applied to said lookup circuit and multiple entries therein, during a search operation. A priority sequencer circuit is also provided. This priority sequencer circuit, which is electrically coupled to outputs of the lookup circuit, is configured to sequentially encode each of the multiple active match signals according to priority.

Abstract: A content addressable memory (CAM) device includes a CAM array, a programmable interconnect structure, and a priority encoder. The CAM array includes a plurality of CAM rows, each row including a number of CAM cells for storing a data word and coupled to a match line that indicates a match result for the CAM row. The programmable interconnect structure is coupled to each CAM row and a plurality of CAM rows, each row including a number of CAM cells for storing a data word and coupled to a match line that indicates match results for the row. The programmable interconnect structure coupled to each CAM row, and is configured to logically connect any number N of selected CAM rows together to form a data word chain spanning N rows, regardless of whether the selected CAM rows are contiguous.

Abstract: A content addressable memory device with a plurality of memory cells storing data words. Each data bit in the data words is set to one of three values of a first binary value, a second binary value, and a don't care value. An aspect of the content addressable memory device is the use of a single memory element and an access device in the memory cells. The memory cells are arranged such that each memory cell is electrically coupled to a single bit line, a single match line, and a single word line. The memory elements in the memory cells store low resistance states if the data bit value is the first binary value, high resistance states if the data bit value is the second binary value, and very high resistance states if the data bit value is the don't care value.

Abstract: A content addressable memory (CAM) device can include a plurality of CAM cells arranged in rows and columns to form multi-byte words. Each CAM cell can include a comparator circuit and one or more data storing circuits. Each comparator circuit can have one or more charge transfer paths arranged between a match line and a first voltage source node. Each data storing circuit can include a write circuit that provides a controllable impedance path between one or more charge transfer paths and a data storage node of the data storing circuit.

Abstract: A semiconductor device includes a CAM cell array that stores the operation setting information as to the semiconductor device, a controller that controls read and write of the CAM cell array, a row decoder, and a column decoder. With this structure, different row addresses are allocated to respective functions of the operation setting information. Accordingly, stress is not caused in the CAM cell array of the unselected functions at the time of programming.

Abstract: A method and circuit to implement a match against range rule functionality. A first rule entry and a second rule entry are stored. The first rule entry includes at least two consecutive identical bits. The first rule entry represents a numerical range. A first field of a binary key is compared with the first rule entry to determine whether any of the bits of the first field are not identical. A logical result of the comparison between the first field and the first rule entry is inverted to generate a first comparison result. A second field of the binary key is compared with a second rule entry to generate a second comparison result. The first comparison result is then logically ANDed with the second comparison result to determine whether the binary key falls within the numerical range represented by the first rule entry and matches the second rule entry.

Abstract: A route lookup system, a TCAM, and an NP are disclosed. A TCAM includes a high-speed serial interface, wherein the TCAM transmits signals through the high-speed serial interface. Embodiments of the present invention generally increase the data transmission rate, reduce the number of signal lines, simplify the PCB design, reduce the chip size, and facilitate PCB wiring. Moreover, the small number of signal lines leads to a decrease of required I/O pins, and reduces the packaging size of the chip.

Abstract: A segmented ternary content addressable memory (TCAM) search architecture is disclosed. In one embodiment, a TCAM device with a row of TCAM cells includes a first segment of the TCAM cells for determining a match of corresponding search bits of a search string with a first portion of a stored string in the first segment of the TCAM cells, an evaluation module for generating a search enable signal if the match of the corresponding search bits with the first portion of the stored string is determined, and a second segment of the TCAM cells for determining a match of remaining search bits of the search string with a remaining portion of the stored string in response to the search enable signal.

Abstract: An integrated circuit device can include a plurality of compare cell circuits that selectively provide charge transfer path between a result line and a reference node according to a comparison between a stored data value and an applied compare data value during a compare time period. A first precharge circuit can have a controllable impedance path coupled between the result line and a precharge voltage node. A control circuit can place the first precharge circuit into a low impedance state during a first portion of the compare time period, and into a high impedance state during a second portion of the compare time period.

Abstract: A CAM column structure includes an interface that drives search data to a plurality of CAM cells via a search line pair. The CAM cells are divided into sections, each section including: a set of CAM cells, a bit line pair coupled to the set of CAM cells, a sense amplifier coupled to the bit line pair, a tri-state read buffer configured to drive read data from the sense amplifier to the search line pair, and a pair of tri-state write buffers configured to drive write data from the search line pair to the bit line pair. In one embodiment, the pair of tri-state write buffers is replaced by a pair of switches that couple the search line pair to the sense amplifier. The search line pair may be segmented by tri-state buffers, which are controlled to drive the search, read and write data along the search line pair.

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 content-addressable random access memory having magnetic tunnel junction-based memory cells and methods for making and using same. The magnetic tunnel junction has first and second magnetic layers and can act as a data store and a data sense. Within each cell, registered data is written by setting a magnetic orientation of the first magnetic layer in the magnetic tunnel junction via current pulses in one or more current lines. Input data for comparison with the registered data can be similarly set through the magnetic orientation of the second magnetic layer via the current lines. The data sense is performed by measuring cell resistance, which depends upon the relative magnetic orientation of the magnetic layers. Since data storage, data input, and data sense are integrated into one cell, the memory combines higher densities with non-volatility. The memory can support high speed, reduced power consumption, and data masking.

Abstract: A content addressable memory (CAM) device includes a plurality of independently configurable CAM groups, each CAM group including a number of CAM rows and a programmable combinational logic circuit. Each CAM row includes a plurality of CAM cells coupled to a match line that generates a row match signal during a compare operation between a search key and data stored in the CAM row. The programmable combinational logic circuit logically combines the row match signals to generate a corresponding group match signal according to a respective one of a plurality of selectable logical operations selected by a corresponding function select signal.

Abstract: A content addressable memory using encoded data words and search words, and techniques for operating such device. In one embodiment, the data word is transformed into a code word guaranteeing a mismatch of at least two code word bits of different binary values during the memory search operation when the data word does not match a search word. In another embodiment, the search word is transformed into a search code such that the Hamming distance between the code word and the search code is greater than a given threshold when there is a mismatch of at least one bit between the data word and the search word.

Abstract: A method and apparatus for multiple string searching using a ternary content addressable memory. For one embodiment, the method includes selecting character groups from an input text string in a temporal sequence, each character group having more than one character. A first character group of the character groups is compared with a plurality of character fields and a current state of a state machine is compared with a plurality of states of the state machine that correspond to the plurality of character fields to identify information indicative of a subsequent state of the state machine. Comparison of the first character group with the plurality of sets of character fields is repeated if the information indicative of the subsequent state of the state machine indicates that a terminal number of characters of a desired character pattern has been located and that the terminal number of characters is fewer than the number of characters in the first character group.

Abstract: An apparatus is equipped with a content addressable memory (CAM) to store one or more key entries corresponding to a data class represented by the CAM. Each of the one or more key entries is associated with a key tag corresponding to one of one or more subclasses of the data class. The apparatus is further equipped with logic coupled to the CAM to extract a data key from a data stream, to compare all or part of the data key with the one or more key entries to determine if the data key is a member of the data class, and to classify the data key as belonging to one of the one or more subclasses of the data class if the data key is determined to be a member of data class.