Patents by Inventor Craig M. Darsow
Craig M. Darsow has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8683402Abstract: A timing analysis mechanism allows defining a clock alias that correlates a clock that is not present in an integrated circuit design to a real clock in the integrated circuit design. In a first implementation, when an existing user assertion references a clock alias, the timing analysis mechanism generates a new user assertion that references the real clock specified in the clock alias. The new user assertion is then used in the timing analysis and the existing user assertion is not. In a second implementation, when an existing user assertion references a clock alias, the timing analysis mechanism generates a duplicate clock in the timing database, preserving all its attributes, and then passes the assertion using the alias name as well as any assertions using the corresponding real clock name to the timing engine to be used in the timing analysis.Type: GrantFiled: November 14, 2012Date of Patent: March 25, 2014Assignee: International Business Machines CorporationInventors: Michael D. Amundson, Craig M. Darsow
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Patent number: 8612910Abstract: A timing analysis mechanism allows defining a clock alias that correlates a clock that is not present in an integrated circuit design to a real clock in the integrated circuit design. In a first implementation, when an existing user assertion references a clock alias, the timing analysis mechanism generates a new user assertion that references the real clock specified in the clock alias. The new user assertion is then used in the timing analysis and the existing user assertion is not. In a second implementation, when an existing user assertion references a clock alias, the timing analysis mechanism generates a duplicate clock in the timing database, preserving all its attributes, and then passes the assertion using the alias name as well as any assertions using the corresponding real clock name to the timing engine to be used in the timing analysis.Type: GrantFiled: November 14, 2012Date of Patent: December 17, 2013Assignee: International Business Machines CorporationInventors: Michael D. Amudson, Craig M. Darsow
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Patent number: 8448113Abstract: A computer implemented method, system and/or computer program product efficiently manage timing parameters in a circuit. Multiple instances of a definition are implemented onto a circuit. A set of related pins from the multiple instances are defined, and a common assertion value is asserted against all pins in the set of related pins.Type: GrantFiled: April 27, 2010Date of Patent: May 21, 2013Assignee: International Business Machines CorporationInventors: Michael D. Amundson, Craig M. Darsow
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Patent number: 8438514Abstract: A timing analysis mechanism allows defining a clock alias that correlates a clock that is not present in an integrated circuit design to a real clock in the integrated circuit design. In a first implementation, when an existing user assertion references a clock alias, the timing analysis mechanism generates a new user assertion that references the real clock specified in the clock alias. The new user assertion is then used in the timing analysis and the existing user assertion is not. In a second implementation, when an existing user assertion references a clock alias, the timing analysis mechanism generates a duplicate clock in the timing database, preserving all its attributes, and then passes the assertion using the alias name as well as any assertions using the corresponding real clock name to the timing engine to be used in the timing analysis.Type: GrantFiled: April 17, 2012Date of Patent: May 7, 2013Assignee: International Business Machines CorporationInventors: Michael D. Amundson, Craig M. Darsow
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Patent number: 8316333Abstract: A computer-implemented method, system, and computer program product are provided for implementing timing pessimism reduction for parallel clock trees. A common path tracing algorithm in a static timing tool is enhanced to include a proximity credit used for pairs of gates in two clock trees that are placed in close proximity to each other. The proximity credit given is equal to a predefined fraction of a proximity component of a gate delay.Type: GrantFiled: July 22, 2010Date of Patent: November 20, 2012Assignee: International Business Machines CorporationInventors: Craig M. Darsow, Timothy D. Helvey
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Patent number: 8271923Abstract: A method, system and computer program product are provided for implementing forward tracing to reduce pessimism in static timing of logic blocks laid out in parallel structures on an integrated circuit chip. A common path pessimism removal algorithm is enhanced by a forward tracing parallel clock tree proximity credit algorithm that uses forward tracing, and computes a proximity credit that is applied to reduce pessimism in the static timing.Type: GrantFiled: July 22, 2010Date of Patent: September 18, 2012Assignee: International Business Machines CorporationInventors: Craig M. Darsow, Timothy D. Helvey
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Patent number: 8250515Abstract: A timing analysis mechanism allows defining a clock alias that correlates a clock that is not present in an integrated circuit design to a real clock in the integrated circuit design. In a first implementation, when an existing user assertion references a clock alias, the timing analysis mechanism generates a new user assertion that references the real clock specified in the clock alias. The new user assertion is then used in the timing analysis and the existing user assertion is not. In a second implementation, when an existing user assertion references a clock alias, the timing analysis mechanism generates a duplicate clock in the timing database, preserving all its attributes, and then passes the assertion using the alias name as well as any assertions using the corresponding real clock name to the timing engine to be used in the timing analysis.Type: GrantFiled: April 29, 2010Date of Patent: August 21, 2012Assignee: International Business Machines CorporationInventors: Michael D. Amundson, Craig M. Darsow
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Publication number: 20120204138Abstract: A timing analysis mechanism allows defining a clock alias that correlates a clock that is not present in an integrated circuit design to a real clock in the integrated circuit design. In a first implementation, when an existing user assertion references a clock alias, the timing analysis mechanism generates a new user assertion that references the real clock specified in the clock alias. The new user assertion is then used in the timing analysis and the existing user assertion is not. In a second implementation, when an existing user assertion references a clock alias, the timing analysis mechanism generates a duplicate clock in the timing database, preserving all its attributes, and then passes the assertion using the alias name as well as any assertions using the corresponding real clock name to the timing engine to be used in the timing analysis.Type: ApplicationFiled: April 17, 2012Publication date: August 9, 2012Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Michael D. Amundson, Craig M. Darsow
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Publication number: 20120023469Abstract: A computer-implemented method, system, and computer program product are provided for implementing timing pessimism reduction for parallel clock trees. A common path tracing algorithm in a static timing tool is enhanced to include a proximity credit used for pairs of gates in two clock trees that are placed in close proximity to each other. The proximity credit given is equal to a predefined fraction of a proximity component of a gate delay.Type: ApplicationFiled: July 22, 2010Publication date: January 26, 2012Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Craig M. Darsow, Timothy D. Helvey
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Publication number: 20120023466Abstract: A method, system and computer program product are provided for implementing forward tracing to reduce pessimism in static timing of logic blocks laid out in parallel structures on an integrated circuit chip. A common path pessimism removal algorithm is enhanced by a forward tracing parallel clock tree proximity credit algorithm that uses forward tracing, and computes a proximity credit that is applied to reduce pessimism in the static timing.Type: ApplicationFiled: July 22, 2010Publication date: January 26, 2012Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Craig M. Darsow, Timothy D. Helvey
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Publication number: 20110271245Abstract: A timing analysis mechanism allows defining a clock alias that correlates a clock that is not present in an integrated circuit design to a real clock in the integrated circuit design. In a first implementation, when an existing user assertion references a clock alias, the timing analysis mechanism generates a new user assertion that references the real clock specified in the clock alias. The new user assertion is then used in the timing analysis and the existing user assertion is not. In a second implementation, when an existing user assertion references a clock alias, the timing analysis mechanism generates a duplicate clock in the timing database, preserving all its attributes, and then passes the assertion using the alias name as well as any assertions using the corresponding real clock name to the timing engine to be used in the timing analysis.Type: ApplicationFiled: April 29, 2010Publication date: November 3, 2011Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Michael D. Amundson, Craig M. Darsow
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Publication number: 20110265052Abstract: A computer implemented method, system and/or computer program product efficiently manage timing parameters in a circuit. Multiple instances of a definition are implemented onto a circuit. A set of related pins from the multiple instances are defined, and a common assertion value is asserted against all pins in the set of related pins.Type: ApplicationFiled: April 27, 2010Publication date: October 27, 2011Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: MICHAEL D. AMUNDSON, CRAIG M. DARSOW
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Patent number: 8024683Abstract: An apparatus, method and program product create multiple copies of a clock signal, or phase, to analyze timing operations within a single timing run of a static timing analysis operation. At least one path comprising logical user defined delay segments and a timing point may be associated with both a common point and no delay. An original clock signal may propagate along the logical path without incurring delay until arriving back at the common point, along with the original signal. All other clocks may be ignored or prevented from propagating long the path. Multiple replicated copies may be accomplished without requiring additional hardware.Type: GrantFiled: May 23, 2008Date of Patent: September 20, 2011Assignee: International Business Machines CorporationInventors: Craig M. Darsow, Timothy D. Helvey
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Patent number: 7962871Abstract: An apparatus, program product and method perform static timing analysis on an integrated circuit design by concurrently modeling a plurality of timing delays associated with a connection between points in the design. The delays are conveyed in multiple clock signals of a single timing run of a static timing analysis operation. Multiple paths comprising logical user defined delay segments are assigned different delays. Only one signal may be permitted to propagate along each path.Type: GrantFiled: May 23, 2008Date of Patent: June 14, 2011Assignee: International Business Machines CorporationInventors: Craig M. Darsow, Timothy D. Helvey
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Publication number: 20090293030Abstract: An apparatus, program product and method perform static timing analysis on an integrated circuit design by concurrently modeling a plurality of timing delays associated with a connection between points in the design. The delays are conveyed in multiple clock signals of a single timing run of a static timing analysis operation. Multiple paths comprising logical user defined delay segments are assigned different delays. Only one signal may be permitted to propagate along each path.Type: ApplicationFiled: May 23, 2008Publication date: November 26, 2009Inventors: Craig M. Darsow, Timothy D. Helvey
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Publication number: 20090293031Abstract: An apparatus, method and program product create multiple copies of a clock signal, or phase, to analyze timing operations within a single timing run of a static timing analysis operation. At least one path comprising logical user defined delay segments and a timing point may be associated with both a common point and no delay. An original clock signal may propagate along the logical path without incurring delay until arriving back at the common point, along with the original signal. All other clocks may be ignored or prevented from propagating long the path. Multiple replicated copies may be accomplished without requiring additional hardware.Type: ApplicationFiled: May 23, 2008Publication date: November 26, 2009Inventors: Craig M. Darsow, Timothy D. Helvey