Abstract: An advanced processor comprises a plurality of multithreaded processor cores each having a data cache and instruction cache. A data switch interconnect is coupled to each of the processor cores and configured to pass information among the processor cores. A messaging network is coupled to each of the processor cores and a plurality of communication ports. In one aspect of an embodiment of the invention, the data switch interconnect is coupled to each of the processor cores by its respective data cache, and the messaging network is coupled to each of the processor cores by its respective message station. Advantages of the invention include the ability to provide high bandwidth communications between computer systems and memory in an efficient and cost-effective manner.

Abstract: A content addressable memory (CAM) may include a plurality of precharge circuits, each coupled to a group of CAM cells and comprising a first precharge path that is temporarily enabled in response to an activated first control signal, and a second precharge path that is temporarily enabled in response to an activated second control signal and a valid indication that indicates whether or not the corresponding group of CAM cells stores valid data, the valid indication being different than the first and second control signals.

Abstract: A search engine searches a database for key candidates having a longest matching prefix with a search key. The search engine includes first stage decoders each having a matrix of interconnected cells for identifying preliminary candidate keys in the database. The search engine also includes a second stage decoder having a matrix of interconnected cells for identifying secondary candidate keys from the preliminary candidate keys. Additionally, the search engine includes a longest candidate prefix module to determine whether one of the secondary candidate keys matches the search key. In some embodiments, the search engine includes a longest prefix match module for identifying the secondary candidate key having a longest matching prefix with the search key.

Abstract: A packet classification device includes a CAM device, an SRAM device, and a control circuit that controls and coordinates the operations of the CAM and SRAM devices. For some embodiments, a first CAM block stores unique entries for each packet header field, a RAM block coupled to the first CAM block stores field labels for the unique packet header fields, a second CAM block stores group labels consisting of unique combinations of concatenated field labels, and a second RAM block coupled to the second CAM block stores a group identification (ID) for each group label, wherein each group ID identifies a corresponding one of the groups of rules.

Abstract: A prefix matching apparatus for directing information to a destination port includes a memory configured to store a piece of data including an address and a plurality of levels each including a plurality of memory locations, the levels each representing a unique address space. A controller is coupled to the memory and to the plurality of levels, and is configured to read the data address and to direct the data to the next level associated with a unique address space associated with the data address. In one embodiment, the controller is configured to match the data address prefix to a plurality of addresses associated with the unique address spaces. Advantages of the invention include fast switch decisions and low switch latency.

Abstract: A network switch includes an input layer to receive a data stream with a set of cells. Each cell includes data and a header to designate a destination device. The input layer includes a set of input layer circuits. A selected input layer circuit of the set of input layer circuits receives the data stream. The selected input layer circuit includes a set of queues corresponding to a set of destination devices. The selected input layer circuit is configured to assign a selected cell from the data stream to a selected queue of the set of queues. The selected queue corresponds to a selected destination device specified by the header of the selected cell. An intermediate layer includes a set of intermediate layer circuits, each intermediate layer circuit has a set of buffers corresponding to the set of destination devices.

Abstract: A content search system includes CAM device, a compiler, and an image loader. The CAM device, which includes a plurality of rows of CAM cells and a number of counter circuits selectively interconnected by a programmable interconnect structure (PRS), performs regular expression search operations. The compiler selectively converts the regular expression into a number of various bit groups, and the image loader loads corresponding bit groups into the CAM cells, into a number of memory elements that control configuration of the PRS, and into the counter circuits.

Abstract: An advanced processor comprises a plurality of multithreaded processor cores each having a data cache and instruction cache. A data switch interconnect is coupled to each of the processor cores and configured to pass information among the processor cores. A messaging network is coupled to each of the processor cores and a plurality of communication ports. In one aspect of an embodiment of the invention, the data switch interconnect is coupled to each of the processor cores by its respective data cache, and the messaging network is coupled to each of the processor cores by its respective message station. Advantages of the invention include the ability to provide high bandwidth communications between computer systems and memory in an efficient and cost-effective manner.

Abstract: A content addressable memory (CAM) device includes an array having a number N of CAM rows, each row including a plurality of CAM cells coupled to a match line, a spare CAM row including a plurality of CAM cells coupled to a spare match line, and row replacement circuitry configured to functionally replace a defective CAM row and each subsequent CAM row in the array with corresponding next adjacent CAM rows, wherein a last CAM row in the array is functionally replaced by the spare CAM row.

Abstract: A memory device operates in a calibration mode during which the effects of bit line leakage current are measured and to operate in a normal mode during which the bit line current is adjusted to compensate for leakage according to the results of the calibration mode. In the calibration mode, a leakage-free sense operation is performed to determine the differential voltage generated on the bit lines in response to a data value. Then, a leakage-susceptible test read operation is performed to determine the differential voltage generated on the bit lines in response to the data value. A detection circuit measures the difference between the differential voltages generated in the leakage-free and leakage-susceptible test read operations to generate a compensation signal, which subsequently adjusts the bit line compensation current during the normal mode.

Abstract: A content addressable memory (CAM) device having any number of rows, each of the rows including a match line connected to a plurality of CAM cells, a match line detector circuit, and a pre-charge circuit. The detector circuit detects a voltage of the match line and generates a feedback signal based on the detected match line voltage. The pre-charge circuit adaptively charges the match line in response to the feedback signal.

Abstract: A content addressable memory (CAM) device includes a CAM array and a configuration circuit. The CAM array has a plurality of rows of CAM cells, each row segmented into a plurality of row segments, each row segment including a plurality of CAM cells coupled to a corresponding match line segment, and a match line control circuit having an input coupled to the corresponding match line segment, an output coupled to the match line segment in a next row segment, and a control terminal to receive a corresponding enable signal. The configuration circuit has an input to receive configuration information indicative of a width and depth configuration of the CAM array and having outputs to generate the enable signals.

Abstract: A comparator circuit is disclosed that determines whether a first binary value is greater than, equal to, and/or less than a second binary value without employing binary adder circuits, and therefore is simpler, occupies less circuit area, and consumes less power than conventional comparator circuits having binary adders. For some embodiments, the comparator circuit is capable of performing full comparison operations on two or more arbitrary binary values. The comparator circuit can be implemented in TCAM devices to perform regular expression search operations.

Abstract: A digital linear voltage regulator includes a comparator, a finite state machine, and a current digital-to-analog converter (DAC). The comparator is preferably coupled to receive a reference voltage and an operating voltage supplied to a dynamic load. The comparator generates, during a clock cycle, a binary output based on a comparison between reference and operating voltages. The finite state machine (FSM) is coupled to receive at least one control signal that indicates a target operating state for the digital linear voltage regulator. The FSM receives the binary output from the comparator and generates a digital word, during a clock cycle, based on the target operating state of the digital linear voltage regulator and on the binary output. The current DAC is coupled to the FSM, receives the digital word and delivers current at the desired voltage to the dynamic load.

Abstract: A storage system and method of operating the same can speed the operation of cache management functions. Generally, a storage system can include data stored in stripes, with each stripe including a number of blocks. A cache memory can store data blocks for fast access. A method can include providing a ternary content addressable memory (TCAM) with a processor coupled thereto, and tracking a block count for each active stripe with the processor and TCAM. The block count for each active stripe can be the number of data blocks belonging to the same stripe that are stored in the cache memory.

Abstract: An apparatus and method of programming a search engine to implement regular expression search operations are disclosed that selectively transform a source regular expression into an equivalent reformulated regular expression in response to a determination of the architectural characteristics of the search engine. In this manner, the regular expression can be reformulated to optimize the configuration and available resources of the associated search engine.

Abstract: A search tree embodying a plurality of signatures to be compared with an input string of characters and including a number of branches of sequential states originating at a root node, wherein each state comprises a state entry including a failure transition and one or more success transitions, is optimized by selecting a failure size parameter indicating a minimum number of characters to be traversed on the failure transitions and selectively modifying the search tree to create a modified search tree for which all failure transitions to non-root states are characterized by the selected failure size parameter.

Abstract: Data and clock synchronization within a gigabit receiver is maintained throughout the data byte processing logic of the receiver by utilizing the same byte clock signal. The deserialization clock signal that is used to deserialize the received serial data stream is phase coherent with the distributed byte clock signal used within the physical coding sublayer (PCS), thus establishing reliable data transfer across the physical media attachment (PMA) and PCS layers of the gigabit receiver while maintaining a known, fixed latency. The phase relationship between a derived bit clock signal and the byte clock signal is shifted in a manner that achieves coarse data alignment within each data byte without affecting the latency. Conversely, the coarse data alignment is combined with a data alignment toggling procedure to reduce data alignment granularity with minimized latency changes.

Abstract: A substrate biasing circuit may include a first pump control circuit that generates a first control signal in response to a first reference voltage and a voltage of a first substrate portion, and includes a first reference generator coupled between a temperature compensated voltage and a reference power supply voltage that varies the first reference voltage in response to the voltage of the first substrate voltage and the temperature compensated voltage. A first clamp circuit may generate a first clamp signal in response to a first limit voltage and the voltage of the first substrate portion, the first limit voltage being a scaled version of the temperature compensated voltage. A first charge pump may pump the first substrate portion in at least a first voltage direction in response to the first control signal, and is prevented from pumping in the first voltage direction in response to the first clamp signal.

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.