John H Downey

US Patent:

6427223, Jul 30, 2002

Filed:

Apr 30, 1999

Appl. No.:

09/303181

Inventors:

Won Sub Kim - Fremont CA
John Harold Downey - San Jose CA
Daniel Marcos Chapiro - Palo Alto CA

Assignee:

Synopsys, Inc. - Mountain View CA

International Classification:

G06F 1750

US Classification:

716 4, 716 5, 716 6

Abstract:

The present invention adds capabilities to a Hardware Verification Language (HVL) which facilitate the monitoring of a device under test (DUT). The HVL language supports Object-Oriented Programming (or OOP). Within this OOP framework, the present invention provides a monitoring facility comprised of three main stages: i) Coverage Definitions, ii) Coverage Instantiation and Triggering and iii) Coverage Feedback. A coverage definition is very similar to an OOP class definition, but does not contain methods or variables. Instead, the basic purpose of a coverage definition is to declare âmonitor binsâ in terms of a state variable. Essentially, each monitor bin declaration has a unique bin name which is associated with a particular behavior of the state variable and the unique bin name is used to record the state variables behavior. Instantiation of a coverage definition produces a coverage instance. Two key instantiation parameters are: an actual state variable that is to be monitored by the instance and a trigger expression which determines when the state variable of the instance is to be monitored.

US Patent:

8201207, Jun 12, 2012

Filed:

Dec 15, 2008

Appl. No.:

12/334777

Inventors:

James S. An - Sunnyvale CA, US
Hui Sun - San Jose CA, US
De Fu Li - Wayland MA, US
Keil Brewer - San Jose CA, US
John J. Downey - Apex NC, US
Chrisanto D. Leano - San Jose CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04N 7/173

US Classification:

725111, 370225, 370252, 370397, 370399, 375219, 375222, 709223, 709224

Abstract:

Disclosed are apparatus and methods for managing upstream channels on a per cable modem basis. In certain embodiments, one or more thresholds are defined for each of a plurality of upstream logical channels of a headend system for receiving data from a plurality of cable modems (or other types of access nodes). Each defined threshold corresponds to a measurable parameter of the corresponding upstream logical channel. One or more metrics are collected for each cable modem of each upstream logical channel. It is determined whether to downgrade a selected cable modem to a selected one of the logical channels that has a lower performance level than the selected cable modem's current logical channel. Such downgrade determination is based on whether the selected cable modem's collected one or more metrics have failed a condition of the one or more defined thresholds and whether a percentage of a total of the cable modems of such current logical channel that have failed a condition for the one or more defined thresholds is less than a predefined percentage level. The selected cable modem is then caused to move from the current logical channel to the selected logical channel when the percentage of the total cable modems that have failed is below a predefined level if such selected logical channel is available.

US Patent:

60060271, Dec 21, 1999

Filed:

Aug 20, 1997

Appl. No.:

8/915285

Inventors:

John H. Downey - San Jose CA

Assignee:

Synopsys, Inc. - Mountain View CA

International Classification:

G06F 9455

US Classification:

39550038

Abstract:

A method and apparatus for inserting an event into a simulation time queue, wherein the simulation time queue is represented by a tree structure having a top node which represents the total number of "time slices" to be simulated, intermediate nodes representing subsets of time slices within the total number of time slices to be simulated, and event locations representing events to be simulated. A time slice is defined to represent a minimum resolvable time period within the simulation. The method includes the steps of choosing a starting node within the tree structure, designating it as the current location, determining whether the current location is an intermediate node representing a range of time slices of which the time slice of the event to be inserted is a subset, determining, if the current location is such an intermediate node, if any existing child nodes of said current location are event locations, and if so, adding the event to the proper event location of said current location.