Netlogic Microsystems, Inc

Broadcom Corporation

Avago Technologies International Sales Pte. Limited

Sachin Joshi

Sandeep Khanna

Varadarajan Srinivasan

Maheshwaran Srinivasan

Mark Birman

Alexei Starovoitov

De Cai Li

Methods, systems and computer readable storage medium embodiments for communicating over a data bus include, determining a number of changes in bit value in respective bit positions between a previous bit string and a current bit string, transmitting either the current bit string in an inverted form over the data bus if the determined number of changes in bit value exceeds a threshold or the current bit string in non-inverted form if the determined number of changes in bit value does not exceed a threshold, and transmitting an additional at least one bit along with the current bit string having a logic value that indicates whether the current bit string is in an inverted form or non-inverted form. Methods, systems, and computer readable storage medium embodiments for receiving bit strings over a bus are also disclosed.

Low power signaling for data transfer

A memory device with word-line voltage boosting includes a set of first switches that are operable to couple a word-line of the memory device to a supply voltage to pull the word-line up to a rail voltage. A dummy line including a conductive route can be disposed in a vicinity of the word-line to form a parasitic coupling capacitance with the word-line. A second switch is operable to couple the dummy line to the supply voltage to pull the dummy line to the rail voltage. Pulling up the dummy line boosts the word-line voltage above the rail voltage by a boost voltage.

Techniques to boost word-line voltage using parasitic capacitances

Embodiments of the present disclosure enable low swing dynamic circuits with reduced dynamic power and leakage power. In an embodiment, a level detector circuit monitors the pre-charge voltage level of the dynamic node of a dynamic circuit and discontinues the charging of the dynamic node when the pre-charge voltage exceeds a logic high reference voltage. The logic high reference voltage is selected below a supply voltage of the dynamic circuit, resulting in a low swing dynamic circuit. In another embodiment, the pull-down logic circuitry is disconnected from the dynamic node when the dynamic node voltage falls below a logic low reference voltage, above a ground voltage. In another embodiment, a DC keeper circuit of the dynamic circuit is configured based on the pre-charge level of the dynamic node.

Low swing dynamic circuit

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.

Compiling regular expressions for programmable content addressable memory devices

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.

Comparator circuit

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.

Reformulating regular expressions into architecture-dependent bit groups

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.

Power reduction in a content addressable memory having programmable interconnect structure

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.

Content addressable memory having selectively interconnected rows of counter circuits

Content addresable memory having selectively interconnected counter circuits

Content addresable memory having programmable interconnect structure

A system for searching an input string for a number of regular expressions includes a search block and a compiler. The search block includes a plurality of content addressable memory (CAM) devices, wherein each of the CAM devices is differently configured to implement search operations for regular expressions having a unique level of complexity. The compiler is configured to determine the complexity level of each of the regular expressions, and is configured to store each regular expression in a selected one of the CAM devices according to its complexity level.

Regular expression search engine

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 is configured to selectively route the match results from a first CAM row as an input match signal to any number of arbitrarily selected CAM rows at the same time.

Growing community of inventors

Fremont, CA, United States of America

Sachin Joshi