Abstract: A CAM device (100) according to an embodiment can include a control circuit (106) that can sequentially activate, with dummy operations, an increasingly larger number of CAM blocks (102-1 to 102-16) in response to a start-up circuit (104) indication until an initial number of CAM blocks is activated. A control circuit (106) can receive a user configurable block number (USER_BLK) and adjust the number of CAM blocks in a sequentially fashion, with dummy operations, until the user configurable number of CAM blocks is being activated. If a received command is targeted to less than the user configurable block number of CAM blocks, a control circuit (106) can activate, with dummy operations, an additional number of CAM blocks so that the total number of CAM blocks activate equals the user configurable block number.
Abstract: A memory/logic cell layout structure includes a pair of memory/logic cells formed on a substrate. Each memory/logic cell (102, 104) can include a pair of memory areas to store data (106-0/106-1, 106-2/106-3), and a logic portion (108-0, 108-1) that receives the data stored therein. Memory areas and the logic portions of each memory/logic cell can be arranged on the substrate in a shape of an L, U, S, T, or Z to form a pair of interlocking memory/logic cells.
Abstract: A digital signal processor having priority logic coupled to an array of storage elements, the priority logic to provide to a priority signal lines an indication of a location of a particular number in the array of storage elements. The priority logic includes compare circuits where each compare circuit is coupled to one of the storage elements in the array of storage elements. Each compare circuit has a first input coupled to a storage element, a second input coupled to a match line, and an input/output line coupled to one of the priority signal lines. The priority logic also includes a delay circuit coupled to each of the compare circuits.
Type:
Grant
Filed:
February 26, 2004
Date of Patent:
September 18, 2007
Assignee:
Netlogic Microsystems, Inc.
Inventors:
Jose P. Pereira, Rupesh Ranen Roy, Varadarajan Srinivasan, Sandeep Khanna, Bindiganavale S. Nataraj
Abstract: A range matching circuit (100) may include a range compare circuit (102) that receives a first range value from a first value store (104) and a second range value from a second range store (106). A range compare circuit (102) can determine if a comparand value falls within a range defined by a first and second range value. A comparand value may also be applied to a compare section (112). A compare section (112) can output an active a match result when a comparand value matches at least one entry in the compare section (112).
Abstract: A traffic management processor includes a departure time calculator for generating a departure time for each packet, a departure time table having a plurality of rows, each having a first portion for storing the departure time for a corresponding packet and having a second portion for storing a rollover bit, and a reset circuit configured to reset the rollover bits in a predetermined time.
Abstract: A content addressable memory (CAM) device including a CAM array, encoding circuit, address circuit and error checking circuit. The encoding circuit generates an address value that corresponds to one of a plurality of match lines included within the CAM array. The address circuit receives the address value from the encoding circuit and enables a data word to be output from a CAM array storage location indicated by the address value. The error checking circuit receives the data word output from the storage location and determines whether the data word contains an error.
Type:
Grant
Filed:
August 11, 2003
Date of Patent:
August 14, 2007
Assignee:
NetLogic Microsystems, Inc.
Inventors:
Varadarajan Srinivasan, Michael E. Ichiriu, Bindiganavale S. Nataraj, Sandeep Khanna
Abstract: A CAM and method for operating a CAM are presented. Copies of a CAM database are duplicated and placed in a first set of CAM locations and a second set of CAM locations. An error detector is used to determine false matches in the case of soft errors within the entries producing those false matches. While the entries producing a match should have the same index location, errors might cause those match lines to have an offset. If so, the present CAM, through use of duplicative sets of CAM locations, will detect the offset and thereafter the values in each index location that produces a match, along with the corresponding parity or error detection encoding bit(s). If the parity or error detection encoding bit(s) indicate an error in a particular entry, then that error is located and the corresponding entry at the same index within the other, duplicative set of CAM locations is copied into the that erroneous entry.
Type:
Grant
Filed:
October 14, 2003
Date of Patent:
August 7, 2007
Assignee:
NetLogic Microsystems, Inc.
Inventors:
Andrew J. Wright, Eric H. Voelkel, Srinivasan Venkatachary, Rochan Sankar
Abstract: A content comparator memory (CCM) device can include a row (100) of CCM cells (102-1 to 102-I). Each CCM cell (102-1 to 102-I) can have a controllable signal path (104-1 to 104-I) arranged in series to form a match path (106) that provides a match indication MATCH that can be activated when a comparand value (CD[1:I]) is determined to match a stored data value. Each CCM cell (102-1 to 102-I) can also be commonly connected to a comparator line (110) that can provide a comparator indication CMP when a compare value (CD[1:I]) has a predetermined magnitude with respect to a stored value.
Abstract: A content addressable memory includes a plurality of CAM blocks, each including an array of CAM cells to store a predetermined range of data values, a parsing circuit having an input to receive the search key and having an output to provide a selected portion of the search key in response to a select signal, and a plurality of block select circuits, each configured to enable a corresponding CAM block if the selected portion of the search key falls within the predetermined range of data values for the corresponding CAM block.
Abstract: A content addressable memory (CAM) device including a CAM array and a priority index table. The CAM array has a plurality of rows of CAM cells, each row including a plurality of row segments and being adapted to store a data word that spans a selectable number of the row segments. The priority index table is coupled to the plurality of rows of CAM cells and is adapted to store a plurality of priority numbers, each priority number being indicative of a priority of a corresponding data word stored in the CAM array.
Type:
Grant
Filed:
June 15, 2005
Date of Patent:
July 17, 2007
Assignee:
NetLogic Microsystems, Inc.
Inventors:
Bindiganavale S. Nataraj, Nilesh A. Gharia, Rupesh R. Roy, Jose P. Pereira, Varadarajan Srinivasan, Sandeep Khanna, Hok F. Wong
Abstract: A content addressable memory (CAM) device having concurrent compare and error checking capability. The content addressable memory (CAM) device includes circuitry to compare a comparand with a plurality of data words stored within the CAM device in a compare operation, and circuitry to determine, concurrently with the compare operation, whether one of the data words has an error.
Abstract: A method and apparatus for input data selection for content addressable memory. In one embodiment, the apparatus includes an array of CAM cells, a select circuit adapted to generate a plurality of select signals each indicative of a segment of input data provided to the CAM apparatus, and switch circuitry including a plurality of programmable switch circuits each programmable to output a respective bit of the input data as a comparand bit for the array of CAM cells in response to one of the select signals.
Abstract: A content addressable memory (CAM) device having a plurality of CAM blocks and a block selection circuit. Each of the CAM blocks includes an array of CAM cells to store data words having a width determined according to a configuration value. The block selection circuit includes an input to receive a class code and circuitry to output a plurality of select signals to the plurality of CAM blocks. Each of the select signals selectively disables a respective one of the plurality of CAM blocks from participating in a compare operation according to whether the class code matches a class assignment of the CAM block.
Type:
Grant
Filed:
October 12, 2004
Date of Patent:
June 12, 2007
Assignee:
NetLogic Microsystems, Inc.
Inventors:
Jose P. Pereira, Varadarajan Srinivasan
Abstract: A content addressable memory (CAM) architecture. For one embodiment, the CAM architecture includes a plurality of rows of CAM cells, each row configured to generate match results on a corresponding match line, a number of comparand lines, each coupled to a corresponding CAM cell in each of the plurality of rows of CAM cells, a plurality of timed storage circuits, each having a data input coupled to a corresponding match line and having an enable input coupled to an enable signal line, a timing generator configured to generate an enable signal on the enable signal line, and a plurality of load elements.
Type:
Grant
Filed:
February 18, 2005
Date of Patent:
June 12, 2007
Assignee:
NetLogic Microsystems, Inc.
Inventors:
Varadarajan Srinivasan, Bindiganavale S. Nataraj, Sandeep Khanna
Abstract: A method for performing a search in a content addressable memory (“CAM”) device comprising comparing a search key with compound entries in a CAM array, wherein at least one of the compound entries includes (i) a ternary CAM word having a data word and a mask word, and (ii) a mask specifier that indicates the state of the mask word, and wherein the search key includes (i) a search word component, and (ii) a search mask component, and wherein the ternary CAM word is compared with the search word and the mask specifier is compared with the search word component; and generating a match signal associated with an compound entry that matches the search key.
Abstract: A pseudo ternary content addressable memory (PTCAM) device (100) can include a number of PTCAM blocks (102-0 to 102-63), each of which can include a number of standard PTCAM rows (106-0 to 106-63) and a standard memory row (104-0 to 104-63) for storing and providing mask information for the PTCAM rows. Redundancy for replacing a defective standard PTCAM row can be provided by a redundant section (108) that include fewer PTCAM rows than in a PTCAM block (102-0 to 102-63). Non-defective PTCAM rows within a standard PTCAM block containing a defective PTCAM row can continue to operate.
Abstract: A CAM includes a plurality of CAM blocks, each including an array of CAM cells divided into a plurality of segments, each array segment for storing a number of data values that are assigned the same priority, a plurality of block priority circuits, each having inputs to receive match signals from a corresponding CAM block and having outputs to generate a block index and priority of a matching data value in the corresponding CAM block assigned the highest priority, and a global priority and index circuit having inputs to receive the block indexes and associated priorities from the block priority circuits, and having an output to generate a device index and associated priority of the highest priority matching value.
Abstract: An semiconductor device having a plurality of fabrication layers. A first region of a first fabrication layer of the semiconductor device is revised. To signal the revision, a connectivity structure in a second region of the first fabrication layer is omitted to interrupt an otherwise continuous signal path that extends through a plurality of interconnection layers of the semiconductor device.
Abstract: A method and apparatus for using a binary CAM array to implement Classless Interdomain Routing (CIDR) Address processing. A binary CAM array is segmented into a plurality of array groups, each of which includes a number of rows of binary CAM cells, a group global mask circuit, and a mask valid bit indicating whether the group global mask circuit stores a valid group global mask.
Type:
Grant
Filed:
January 25, 2005
Date of Patent:
May 1, 2007
Assignee:
Netlogic Microsystems, Inc.
Inventors:
Varadarajan Srinivasan, Bindiganavale S. Nataraj, Sandeep Khanna