Source: http://www.google.com/patents/US6795788?dq=5311516
Timestamp: 2015-04-19 22:01:41
Document Index: 181298662

Matched Legal Cases: ['art 300', 'art 300', 'art 300', 'art 300', 'art 300', 'art 400', 'art 300', 'art 300']

Patent US6795788 - Method and apparatus for discovery of operational boundaries for shmoo tests - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsMethod and apparatus for discovery of operational boundaries for shmoo tests. Specifically, a method of testing operational boundaries is described in one embodiment of the present invention. The method discloses the discovery of an operational range for a hardware device over a plurality of varying...http://www.google.com/patents/US6795788?utm_source=gb-gplus-sharePatent US6795788 - Method and apparatus for discovery of operational boundaries for shmoo testsAdvanced Patent SearchPublication numberUS6795788 B2Publication typeGrantApplication numberUS 10/028,039Publication dateSep 21, 2004Filing dateDec 20, 2001Priority dateJun 6, 2000Fee statusLapsedAlso published asUS20030120451Publication number028039, 10028039, US 6795788 B2, US 6795788B2, US-B2-6795788, US6795788 B2, US6795788B2InventorsPaul A. Thatcher, Gopikrishna JandhyalaOriginal AssigneeHewlett-Packard Development Company, L.P.Export CitationBiBTeX, EndNote, RefManPatent Citations (2), Non-Patent Citations (2), Referenced by (7), Classifications (32), Legal Events (6) External Links: USPTO, USPTO Assignment, EspacenetMethod and apparatus for discovery of operational boundaries for shmoo tests
US 6795788 B2Abstract
What is claimed is: 1. A method of testing operational boundaries comprising:
discovering an operational range over a plurality of varying operating parameters for a device by testing points, as defined by said plurality of varying operating parameters, beginning from a known interior operational point as a single starting point when fully testing said device, to discover adjacently coupled boundary points that define an operational boundary of said device that comprises a plurality of boundary points just outside of said operational range, without testing all of a plurality of interior operational points within said operational boundary. 2. The method of testing operational boundaries as described in claim 1, further comprising:
automatically discovering said operational range by automatically testing for said operational boundary. 3. The method of testing operational boundaries as described in claim 1, further comprising:
varying a first and second parameter in said plurality of varying parameters; and holding constant all remaining parameters in said plurality of varying parameters. 4. The method of testing operational boundaries as described in claim 1, further comprising:
i) beginning from said known interior operational point, testing adjacently coupled points in a first direction until an initial failure point is discovered, said initial failure point being one of said plurality of boundary points; and ii) from said initial failure point, testing for and discovering each of said plurality of boundary points that are adjacently coupled until returning to said initial failure point. 5. The method of testing operational boundaries as described in claim 4, wherein said first direction varies in only one of said plurality of varying parameters in an increasing manner, holding all remaining parameters in said plurality of varying parameters constant.
beginning from a last known boundary point, testing adjacent points in a circular direction starting from known and adjacent interior operational points until a new failure point is discovered, said new failure point being one of said plurality of boundary points; and recursively testing adjacent points in said circular direction with each newly discovered new failure point until again reaching said initial failure point. 7. The method of testing operational boundaries as described in claim 6, wherein said circular direction is a clockwise direction.
setting an upper and lower limit for each of said varying parameters that define operational limits of said operational boundary, wherein points lying outside of said operational limits are points of operational failure. 9. The method of testing operational boundaries as described in claim 1, wherein each of said plurality of boundary points and operational points of failure indicate said device does not successfully boot up and run test applications, and each of said plurality of interior operational points that have been tested indicate said device does successfully boot up and run test applications.
determining whether said plurality of boundary points is part of an interior fault region within said operational boundary; and discovering a second operational boundary of said device that comprises a second plurality of boundary points just outside of said operational range if said plurality of boundary points is part of said interior fault region. 11. A method of testing operational boundaries, comprising:
a) varying a first and second operating parameter in a plurality of operating parameters, said plurality of operating parameters defining points in an operating region for a device; b) beginning from a known operational point of said device as a starting point when fully testing said device, testing adjacently coupled points in a direction until an initial failure point is discovered; and c) from said initial failure point, testing for and discovering each of a plurality of failure points that are adjacently coupled until returning to said initial failure point, said plurality of failure points defining an operational boundary for said device that bounds an operational range comprising a plurality of interior operational points within said operating region for said device. 12. The method of testing operational boundaries as described in claim 11, wherein a), b), and c) are performed automatically.
beginning from a last known boundary point, testing adjacent points in a circular direction starting from known and adjacent interior operational points until a new failure point is discovered, said new failure point being one of said plurality of boundary points; and recursively testing adjacent points in said circular direction with each newly discovered new failure point until again reaching said initial failure point. 15. The method of testing operational boundaries as described in claim 11, further comprising:
d) discovering if said plurality of failure points bound an interior fault region within said operational range; and e) testing for a second plurality of failure points if all of known said plurality of interior operational points do not lie within said plurality of failure points. 16. The method of testing operational boundaries as described in claim 15, wherein d) comprises:
discovering said interior fault region, if a last point that has been tested in a set of adjacent points that are examined from said beginning point to an operational limit in said direction is an operational point. 17. The method of testing operational boundaries as described in claim 16, wherein e) comprises:
beginning from said last point, testing for and discovering each of a second plurality of failure points that are adjacently coupled until returning to said last point, said second plurality of failure points defining a second operational boundary that bounds said operational range within said operating region for said device. 18. The method of testing operational boundaries as described in claim 11, wherein said device is a chip forming an integrated circuit.
discovering the type of fault at each of said plurality of failure points. 20. The method of testing operational boundaries as described in claim 11, wherein said plurality of operating parameters is taken from a group consisting of:
frequency; voltage; current; and temperature. 21. A computer system comprising:
a processor; and a computer readable memory coupled to said processor and containing program instructions that, when executed, implement a method of testing operational boundaries comprising: discovering an operational range over a plurality of varying operating parameters for a device by testing points, as defined by said plurality of varying operating parameters, beginning from a known interior operational point as a single starting point when fully testing said device, to discover adjacently coupled boundary points that define an operational boundary of said device that comprises a plurality of boundary points just outside of said operational range, without testing all of a plurality of interior operational points within said operational boundary. 22. The computer system as described in claim 21, wherein said method further comprises:
automatically discovering said operational range by automatically testing for said operational boundary. 23. The computer system as described in claim 21, wherein said method further comprises:
varying a first and second parameter in said plurality of varying parameters; and holding constant all remaining parameters in said plurality of varying parameters. 24. The computer system as described in claim 21, wherein said method further comprises:
i) beginning from said known interior operational point, testing adjacently coupled points in a first direction until an initial failure point is discovered, said initial failure point being one of said plurality of boundary points; and ii) from said initial failure point, testing for and discovering each of said plurality of boundary points that are adjacently coupled until returning to said initial failure point. 25. The computer system as described in claim 24, wherein said first direction varies in only one of said plurality of varying parameters in an increasing manner, holding all remaining parameters in said plurality of varying parameters constant.
beginning from a last known boundary point, testing adjacent points in a circular direction starting from known and adjacent interior operational points until a new failure point is discovered, said new failure point being one of said plurality of boundary points; and recursively testing adjacent points in said circular direction with each newly discovered new failure point until again reaching said initial failure point. 27. The computer system as described in claim 26, wherein said circular direction is a clockwise direction.
setting an upper and lower limit for each of said varying parameters that define operational limits of said operational boundary, wherein points lying outside of said operational limits are points of operational failure. 29. The computer system as described in claim 21, wherein each of said plurality of boundary points and operational points of failure indicate said device does not successfully boot up and run test applications, and each of said plurality of interior operational points that have been tested indicate said device does successfully boot up and run test applications.
determining whether said plurality of boundary points is part of an interior fault region within said operational boundary; and discovering a second operational boundary of said device that comprises a second plurality of boundary points just outside of said operational range if said plurality of boundary points is part of said interior fault region.
Prior art FIG. 1 is a plot diagram 100 illustrating tested points within a predefined testing region. In the diagram 100, two operating parameters are varied. Points designated by the letter �F� indicate a failure by the hardware component. Points designated by a �dot� indicate an successful operation by the hardware component. The testing region is defined by a first operating parameter on the horizontal axis, and a second operating parameter on the vertical axis, and includes all the points in diagram 100. The first operating parameter varies with values ranging from 3.3 to 3.465. The second operating parameter varies with values ranging from 1.71 to 1.80. These parameters can include input/output voltages, clock frequencies, and temperature, etc.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the present invention, discussions utilizing terms such as �testing,� or �discovering,� or �varying,� or �storing,� or �inputting,� or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
Referring now to FIG. 2, the plot diagram 200 illustrates the discovery of an operational boundary for an electronic device, in accordance with one embodiment of the present invention. In the diagram 200, two operating parameters are varied. Points designated by the letter �F� indicate a failure by the electronic device. Points designated by a dot (�.�) indicate a successful operation by the electrical device.
The diagram 200 in FIG. 2 illustrates an operational boundary 250 of the electronic device. The boundary 250 is defined by the continuous and adjacent pattern of plotted �Fs.� Table 1 shows the coordinates, as defined by the first and second parameters 210 and 220, for each of the plurality of boundary points of the operational boundary 250.
Initial Failure Point
3.10-3.80
Referring now to FIG. 3, to discover the operational boundary of an electronic device, the present embodiment begins at a known operational point, a starting point, in step 310. The known operational point is predefined by a user, and is known to be within the operational boundary of the electronic device. For example, referring to FIG. 2, a known operational point is the point (�x�) at coordinates (1.95, 3.50).
Continuing with step 310, the present embodiment tests adjacently coupled points in a first direction. In one embodiment, the direction is defined by varying one parameter in an increasing manner from the starting point. All the other parameters in the plurality of parameters that could affect the electronic device are held constant. Referring now to FIG. 2, beginning from the starting point �x�, the direction proceeds upwards in diagram 200 by varying the second operating parameter 220 in an increasing manner. All the other plurality of parameters, including the first parameter 210, are held constant. Other embodiments are well suited to any number of directions, e.g., varying the one parameter in decreasing fashion, or varying one or more parameters in linear and non-linear manners, etc.
The process is repeated for every new failing point that is discovered. In condition step 350, the present embodiment determines if the point discovered is a new failing point. If the discovered failing point is a new failing point, then the flow chart 300 proceeds to condition step 360. If the discovered failing point is not a new failing point, it is necessarily the beginning point, and the flow chart 300 proceeds to �A,� as disclosed in FIG. 4, to determine if the operational boundary is part of an interior fault region.
If the new failing point is the initial failing point, then flow chart 300 determines if the new failing point was approached following in the first direction, in condition step 370. This is accomplished to test for an anomalous operational boundary having boundary points possibly separated from other points in the plurality of boundary points by a single operational point. This embodiment ensures proper discovery of the entire boundary region that defines the operational range of the tested electronic device. As such, if the new failing point was approached in the first direction, then flow chart 300 proceeds to �A,� as disclosed in FIG. 4. On the other hand, if the new failing point is the initial failing point, but was not approached in the first direction, then the flow chart 300 proceeds to step 390.
On the other hand, if the last point was an operational point, then the present embodiment proceeds to step 430. In this case, the process outlined in flow chart 400 has determined that the plurality of boundary points lies within an interior fault region. As such, the present embodiment sets the last point as the start point in step 430 and begins the process in flow chart 300 again. Specifically, from step 430, the present embodiment proceeds to �B,� which leads back to step 310 in flow chart 300.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS6079038 *Apr 24, 1998Jun 20, 2000Credence Systems CorporationMethod for generating a Shmoo plot contour for integrated circuit testerUS6418387 *Jun 28, 1999Jul 9, 2002Ltx CorporationMethod of and system for generating a binary shmoo plot in N-dimensional space* Cited by examinerNon-Patent CitationsReference1 *Hamada et al., A High-speed Boundary Search by Shmoo Plot for ULSI Memories, Jan. 1993, IEEE, vol: 4150, pp. 4-9.2 *Niggemeyer et al., Parameteric Built-In-Self-Test of VLSI Systems, Jan. 1999, University of Hannover, pp. 1-5.** Cited by examinerReferenced byCiting PatentFiling datePublication dateApplicantTitleUS7222274 *Feb 25, 2004May 22, 2007International Business Machines CorporationTesting and repair methodology for memories having redundancyUS7299381 *Mar 17, 2004Nov 20, 2007Micron Technology, Inc.Discrete tests for weak bitsUS7519878Nov 22, 2005Apr 14, 2009Teradyne, Inc.Obtaining test data for a deviceUS7711524 *Dec 19, 2005May 4, 2010Verigy (Singapore) Pte. Ltd.Estimating boundaries of Schmoo plotsUS7797596 *Sep 26, 2007Sep 14, 2010Oracle America, Inc.Method for monitoring and adjusting circuit performanceUS8788697 *Feb 12, 2007Jul 22, 2014Panasonic CorporationFile transmitting apparatus, file transmitting method, file receiving apparatus, file receiving method, and file transfer systemUS20110119010 *Jan 15, 2009May 19, 2011Advantest CorporationMethod of determining characteristics of device under test, program, and storage medium storing program* Cited by examinerClassifications U.S. Classification702/119, 714/718, 438/17, 702/58, 702/108, 438/5, 324/612, 324/601, 438/14, 714/709, 714/724, 702/183, 324/439, 324/762.02International ClassificationG01R31/3183, G01R31/317, G01R31/319, G01R31/3193Cooperative ClassificationG01R31/31711, G01R31/318307, G01R31/31908, G01R31/3191, G01R31/31901, G01R31/318371, G01R31/31937European ClassificationG01R31/319C4C, G01R31/3193T, G01R31/3183A, G01R31/3183M, G01R31/319C4, G01R31/319A, G01R31/317J5Legal EventsDateCodeEventDescriptionNov 13, 2012FPExpired due to failure to pay maintenance feeEffective date: 20120921Sep 21, 2012LAPSLapse for failure to pay maintenance feesMay 7, 2012REMIMaintenance fee reminder mailedMar 21, 2008FPAYFee paymentYear of fee payment: 4Sep 30, 2003ASAssignmentOwner name: HEWLETT-PACKARD DEVELOPMENT COMPANY L.P., TEXASFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;REEL/FRAME:014061/0492Effective date: 20030926Owner name: HEWLETT-PACKARD DEVELOPMENT COMPANY L.P. 20555 SHFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY /AR;REEL/FRAME:014061/0492B-Owner name: HEWLETT-PACKARD DEVELOPMENT COMPANY L.P.,TEXASFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;US-ASSIGNMENT DATABASE UPDATED:20100203;REEL/FRAME:14061/492Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;US-ASSIGNMENT DATABASE UPDATED:20100223;REEL/FRAME:14061/492Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;US-ASSIGNMENT DATABASE UPDATED:20100302;REEL/FRAME:14061/492Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;US-ASSIGNMENT DATABASE UPDATED:20100316;REEL/FRAME:14061/492Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;US-ASSIGNMENT DATABASE UPDATED:20100323;REEL/FRAME:14061/492Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;US-ASSIGNMENT DATABASE UPDATED:20100330;REEL/FRAME:14061/492Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;US-ASSIGNMENT DATABASE UPDATED:20100406;REEL/FRAME:14061/492Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;US-ASSIGNMENT DATABASE UPDATED:20100413;REEL/FRAME:14061/492Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;US-ASSIGNMENT DATABASE UPDATED:20100420;REEL/FRAME:14061/492Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;US-ASSIGNMENT DATABASE UPDATED:20100427;REEL/FRAME:14061/492Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;US-ASSIGNMENT DATABASE UPDATED:20100504;REEL/FRAME:14061/492Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;US-ASSIGNMENT DATABASE UPDATED:20100511;REEL/FRAME:14061/492Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;US-ASSIGNMENT DATABASE UPDATED:20100525;REEL/FRAME:14061/492Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HEWLETT-PACKARD COMPANY;REEL/FRAME:14061/492Mar 12, 2002ASAssignmentOwner name: HEWLETT-PACKARD COMPANY, COLORADOFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:THATCHER, PAUL A.;JANDHYALA, GOPIKRISHNA;REEL/FRAME:012717/0674Effective date: 20011218Owner name: HEWLETT-PACKARD COMPANY P.O. 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