Broadcom Corporation

Christopher Gronlund

Mark Jon Winter

Eric Hall

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.

Reduced power consumption content-addressable memory

A disclosed embodiment is an interruptible write block comprising a primary register having an input coupled to an input of the interruptible write block, a secondary register having an input selectably coupled to an output of the primary register and to an output of the secondary register through an interrupt circuit. The interrupt circuit is utilized to interrupt flow of new data from the primary register to the secondary register during an interrupt of a write operation, such that upon resumption of the write operation the secondary register contains valid data. A method of utilizing an interruptible write block during a write operation comprises loading data into a primary register, interrupting the write operation to perform one or more other operations, loading the data into a secondary register while loading new data into the primary register, and resuming the write operation using valid data from the secondary register.

Interruptible write block

A content addressable memory (CAM) system configured for reduced power consumption and increased speed includes a plurality of bit cells implementing a stacked architecture. Each bit cell comprises a pair of stacked storage elements in a first column and a compare circuit, coupled to the pair of stacked storage elements and a matchline of the CAM system, situated in a second column. The stacked architecture results in a reduced matchline length, thereby reducing CAM system power consumption and increasing CAM system speed. Further, a content addressable memory (CAM) system configured for reduced power consumption and increased speed includes storing encoded data in a pair of stacked storage elements.

Low power content-addressable memory

System and method for reducing power consumption in a content-addressable memory

A content addressable memory (CAM) system configured for reduced power consumption and increased speed includes a plurality of bit cells implementing a stacked architecture. Each bit cell comprises a pair of stacked storage elements in a first column and a compare circuit, coupled to the pair of stacked storage elements and a matchline of the CAM system, situated in a second column. The stacked architecture results in a reduced matchline length, thereby reducing CAM system power consumption and increasing CAM system speed. In a further embodiment, a content addressable memory (CAM) system configured for reduced power consumption and increased speed includes storing encoded data in a pair of stacked storage elements.

System for reducing power consumption and increasing speed of content-addressable memory

Interruptible write block and method for using same

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.

N-way mode content addressable memory array

Disclosed is a double data rate (DDR) input block comprising first and second input registers corresponding to a DDR input of the DDR input block. The first and second input registers are coupled to the DDR input. The DDR input block is configured to load a first data into the first input register and a second data into the second input register during a single clock cycle of a system clock, thereby operating at double data input during a single clock cycle. A single data rate/double data rate (SDR/DDR) input block may be operated in either SDR or DDR mode. The DDR input block may he used with a scannable output reduction block. The DDR input block may be used in systems utilizing a content addressable memory (CAM) or a random access memory (RAM), or other types of memory devices.

Double data rate-single data rate input block and method for using same

A disclosed embodiment is a range checking CAM array comprising a plurality of words, where each of the plurality of words comprises a plurality of bound check cells. Each of the plurality of bound check cells outputs a corresponding plurality of match signals and a corresponding plurality of bound check signals. The corresponding plurality of match signals and corresponding plurality of bound check signals are combined to produce a range check output indicating whether data on a data input bus is within a target range. The plurality of bound check cells may be coupled to form at least one cascade of bound check cells, where each cascade of bound check cells may be terminated at a ripple logic. The CAM array produces a final range check output based on the corresponding plurality of match signals and the corresponding plurality of bound check signals.

Growing community of inventors

Kent, WA, United States of America

Christopher Gronlund