Mark J Ross

US Patent:

6526474, Feb 25, 2003

Filed:

Nov 9, 1999

Appl. No.:

09/437012

Inventors:

Mark A. Ross - San Carlos CA

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

G06F 1208

US Classification:

711108, 711158

Abstract:

The invention provides a method and system for operating a CAM with a variable size input tag. The improved CAM has multiple access sizes and is divided into multiple stored match sections. Each of the multiple stored match sections can be independently matched against a portion of the input tag, responsive to a type field for each entry. A size selection circuit accumulates the independent match results; a priority encoder coupled thereto collects the accumulated matches and presents a match as an output from the CAM. Each CAM entry can be selected from a set of preselected sizes, each corresponding to a contemplated input tag size, such as 72 bits, 144 bits, or 288 bits.

US Patent:

6535951, Mar 18, 2003

Filed:

Feb 29, 2000

Appl. No.:

09/515578

Inventors:

Mark A. Ross - San Carlos CA

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

G06F 1202

US Classification:

711108, 711103, 711151, 711154

Abstract:

The invention provides a method and system for performing additional processing on CAM hit results, in which the additional processing does not add to the complexity or size of the CAM chip, can be altered after manufacture of the CAM chip, and does not delay other operations of the CAM. The CAM hit results are presented as indices from the CAM and sent to a hit result register file where they are stored. The contents of the hit result register file can be processed by other hardware or software coupled to the CAM. The index associated with the CAM input tag can be accessed using the hit result register file and a register indirect operation. The index associated with the CAM input tag can be used for CAM management functions in conjunction with (such as in parallel or pipelined) other CAM functions.

US Patent:

6658002, Dec 2, 2003

Filed:

Jun 17, 1999

Appl. No.:

09/335800

Inventors:

Mark A. Ross - San Carlos CA
Sun-Den Chen - San Jose CA
Andreas V. Bechtolsheim - Incline Village NV

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04L 1256

US Classification:

370392

Abstract:

An apparatus and method for performing logical operations on information in the communications protocol stack, such as the transport layer (L4) port numbers, characterizing a received packet or frame of data in a data communications device such as a router or switch. The results of the logical operations, along with other packet/frame-identifying data, are used to generate a more efficient lookup key. A content addressable memory (CAM) lookup is used to determine the action indicated by the rules defined by a rule-based routing or switching scheme, such as an access control list (ACL). The results of these logical operations extend the key space and thus provide a finer-grained match between the original, unextended input key and a rule action, thereby pointing to a rule action precisely tailored to packet processing. The rule can thus be applied with fewer CAM entries, providing the versatility improvement and CAM cost reduction necessary to keep up with the ever-increasing rule complexity requirements of advanced data communication and internetworking systems. An embodiment utilizing asymmetrical processing of packets, depending on whether the packet is inbound to the data communications device or outbound from it, is also disclosed.

US Patent:

6738862, May 18, 2004

Filed:

Apr 29, 2002

Appl. No.:

10/135711

Inventors:

Mark A. Ross - San Carlos CA
Andreas V. Bechtolsheim - Woodside CA

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

G06F 1200

US Classification:

711108, 365 49

Abstract:

The invention provides a method and system for flexible matching of data in a CAM, that does not use the overhead of one mask bit for each matched value bit. The entries of the CAM are logically grouped in a set of blocks, each block having a single mask that applies to all entries in the block. Each block includes a predetermined number of CAM entries, such as a block of 16 entries. However, in alternative embodiments, the number of CAM entries for each block could be predetermined to be a different number, or could be dynamically selected with the values that are entered into the CAM.

US Patent:

6985964, Jan 10, 2006

Filed:

Dec 22, 1999

Appl. No.:

09/469409

Inventors:

Brian A. Petersen - San Francisco CA, US
Mark A. Ross - San Carlos CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

G06F 15/173
G06F 15/16
G06F 7/00
G06F 17/30
G06F 11/00
H04L 12/28

US Classification:

709244, 709224, 709236, 709238, 709239, 707 3, 370238, 370389, 370392, 37039532

Abstract:

A general purpose, software-controlled central processor (CP) can be augmented by a set of task specific, specialized peripheral processors (PPs). The central processor accomplishes its functions with the support of the PPs. Peripheral processors may include but are not limited to a packet parser, a packet deconstructor, a search engine, and a packet editor. At each step in the use of this network processor system, the central processor has an opportunity to intervene and modify the handling of the packet based on its interpretation of PP results. The programmable nature of the CP and the PPs provides the system with flexibility and adaptability.

US Patent:

7260673, Aug 21, 2007

Filed:

Jul 20, 2001

Appl. No.:

09/910227

Inventors:

Mark A. Ross - San Carlos CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

G06F 12/00

US Classification:

711108, 365 49, 714 6

Abstract:

Methods and apparatus are disclosed for verifying the integrity of an index or result produced by a content-addressable or associated memory or other device. A pre-computed data protection field is stored, either as part of a returned index of a content-addressable memory or in a separate storage. In one implementation, a data protection operation is performed on all or part of the returned index and a comparison is made with a pre-computed data protection field. In one implementation, a copy of the masks employed by a ternary content-addressable memory and a set of pre-computed data protection fields are stored. A particular mask and pre-computed data protection field are selected based on the generated index. The original input value is then masked by the selected mask and provided to a data protection function. The result of this function is then compared to the selected pre-computed data protection field.

US Patent:

7343510, Mar 11, 2008

Filed:

Dec 21, 2004

Appl. No.:

11/019731

Inventors:

Mark Ross - San Carlos CA, US
S. Babar Raza - San Jose CA, US
Dimitris Pantelakis - Austin TX, US
Anup Nayak - Fremont CA, US
Walter Bridgewater - San Jose CA, US

Assignee:

Cypress Semiconductor Corporation - San Jose CA

International Classification:

G06F 1/12

US Classification:

713500, 713400, 713502, 713503, 327 1, 327 48, 331 11

Abstract:

A clock detection and selection circuit () can include a first counter (-) that generates a first count value CNT according to a first clock signal CLK and a second counter (-) that generates a second count value CNT according to a second clock signal CLK. First separation-detect logic (-) and second separation-detect logic (-) determine if a pre-specified difference exists between a first count value (CNT/CNT′) and second count value (CNT/CNT′). According to such determinations, separation information (INF and INF) can be generated indicating which clock signal (CLK or CLK) is faster. Selection logic () can select a faster of the clock signals (CLK or CLK) if the separation information values confirm one another.

US Patent:

7653342, Jan 26, 2010

Filed:

Feb 16, 2006

Appl. No.:

11/355816

Inventors:

Timothy C. Nichols - Los Altos CA, US
Mark Andrew Ross - San Carlos CA, US
Clare Lawson - Los Altos CA, US
Arthur Anthonie van Hoff - Menlo Park CA, US

Assignee:

Dell Products L.P. - Round Rock TX

International Classification:

H04H 1/00
H04B 15/00
H04B 1/18
H04K 11/00

US Classification:

455 301, 455 661, 455344, 4551802

Abstract:

Providing content to a device. Content stored on a device can be examined or searched based on the programming of channels that are available to the device over various networks. The content can be searched using other rules related to user preferences or content characteristics. Based on the results of the examination of the content, playlists are generated. Each playlist includes content from the device that matches or partially matches the content associated with one of the channels. Using the playlists, a user can load content from their device that has a theme consistent with a particular channel. When signal loss is detected for a given channel, the playlist associated with that channel can be loaded and played by the device. The device can resume playing the channel when the signal is again adequately detected.