Xin A Li

US Patent:

7487486, Feb 3, 2009

Filed:

Jun 11, 2005

Appl. No.:

11/629445

Inventors:

Mustafa Celik - Santa Clara CA, US
Jiayong Le - Mountain View CA, US
Lawrence Pileggi - Pittsburgh PA, US
Xin Li - Pittsburgh PA, US

International Classification:

G06F 17/50
G06F 7/60
G06F 7/52

US Classification:

716 6, 716 4, 716 5, 703 2, 708607

Abstract:

The large-scale process and environmental variations for today's nano-scale ICs are requiring statistical approaches for timing analysis and optimization (). Significant research has been recently focused on developing new statistical timing analysis algorithms (), but often without consideration for how one should interpret the statistical timing results for optimization. The invention provides a sensitivity-based metric () to assess the criticality of each path and/or arc in the statistical timing graph (). The statistical sensitivities for both paths and arcs are defined. It is shown that path sensitivity is equivalent to the probability that a path is critical, and arc sensitivity is equivalent to the probability that an arc sits on the critical path. An efficient algorithm with incremental analysis capability () is described for fast sensitivity computation that has a linear runtime complexity in circuit size. The efficacy of the proposed sensitivity analysis is demonstrated on both standard benchmark circuits and large industry examples.

US Patent:

7653524, Jan 26, 2010

Filed:

Aug 22, 2005

Appl. No.:

11/208844

Inventors:

Xin Li - Pittsburgh PA, US
Yang Xu - San Diego CA, US
Peng Li - College Station TX, US

Assignee:

Carnegie Mellon University - Pittsburgh PA

International Classification:

G06F 17/50

US Classification:

703 14, 703 4

Abstract:

Analog and radio frequency system-level simulation using frequency relaxation. Embodiments of the invention use a frequency relaxation approach for analog/RF system-level simulation that accommodates both large system size and complex signal space. The simulator can determine an output response for a system by partitioning the system into blocks and simulating the propagation of an input signal through the blocks. The input signal can take various forms, including a multi-tone sinusoidal signal, a continuous spectra signal, and/or a stochastic signal. Frequency relaxation is applied to produce individual responses. The output response can be computed based on obtaining convergence of the individual responses. The input to embodiments of the simulator can be a circuit netlist, or a block-level macromodel.

US Patent:

7669150, Feb 23, 2010

Filed:

Oct 7, 2005

Appl. No.:

11/245892

Inventors:

Xin Li - Pittsburgh PA, US
Larry Pileggi - Pittsburgh PA, US

Assignee:

Xigmix, Inc. - Pittsburgh PA

International Classification:

G06F 17/50
G06F 9/45

US Classification:

716 2, 716 5

Abstract:

A computer implemented method of performing projection based polynomial fitting. The method includes generating a plurality of sampling points as a function of variables. The method also includes forming a polynomial model template representative of the plurality of sampling points. According to embodiments of the present invention, the polynomial model template comprises at least one polynomial coefficient. The method further includes forming a low-rank matrix to approximate the polynomial coefficient.

US Patent:

7826258, Nov 2, 2010

Filed:

Mar 24, 2008

Appl. No.:

12/079036

Inventors:

Jian-Gang Zhu - Pittsburgh PA, US
Yi Luo - Pittsburgh PA, US
Xin Li - Pittsburgh PA, US

Assignee:

Carnegie Mellon University - Pittsburgh PA

International Classification:

G11C 11/14

US Classification:

365171, 365173, 365158, 365 55, 365130

Abstract:

A magnetic memory or MRAM memory system comprising an M×N crossbar array of MRAM cells. Each memory cell stores binary data bits with switchable magnetoresistive tunnel junctions (MJT) where the electrical conductance changes as the magnetic moment of one electrode (the storage layer) in the MJT switches direction. The switching of the magnetic moment is assisted by a phase transition interlayer that transitions from antiferromagnetic to ferromagnetic at a well defined, above ambient temperature.

US Patent:

7908131, Mar 15, 2011

Filed:

Oct 31, 2006

Appl. No.:

11/554887

Inventors:

Xin Li - Pittsburgh PA, US
Peng Li - College Station TX, US
Lawrence T. Pileggi - Pittsburgh PA, US

Assignee:

Carnegie Mellon University - Pittsburgh PA

International Classification:

G06F 7/60
G06F 17/50
G06F 17/10

US Classification:

703 13, 703 2, 703 14, 703 16, 716 1, 716 2, 716 4, 716 5

Abstract:

The present invention is a method and apparatus for creating a reduced-order IC interconnect model, which incorporates variations in interconnect process parameters, and models both on-chip and off-chip interconnects. The method is based on mathematically representing an IC interconnect system, including mathematical interconnect process parameter terms, which are manipulated to facilitate simplification of an IC interconnect model. The IC interconnect model is then simplified by using a mathematical technique called state-space projection. Specifically, an IC interconnect system is represented with at least one modified nodal analysis equation (MNA) that is based on frequency, interconnect process parameters are added and substituted back into the MNA(s), terms with interconnect process parameters are explicitly matched. A state-space projection is created, which implicitly matches frequency terms. The state-space projection is used to create the reduced-order IC interconnect model.

US Patent:

7945868, May 17, 2011

Filed:

Oct 1, 2008

Appl. No.:

12/243176

Inventors:

Lawrence T. Pileggi - Pittsburgh PA, US
Xin Li - Pittsburgh PA, US

Assignee:

Carnegie Mellon University - Pittsburgh PA

International Classification:

G06F 17/50

US Classification:

716 30, 716100, 716101, 716104, 716110, 716115, 716132, 716136, 716138, 703 2, 703 13, 703 14, 326 26, 326 27, 327 51, 327 52, 327 53, 327 63, 327 66, 327246

Abstract:

The invention discloses a method for tuning nano-scale analog-circuit designs in order to reduce random-device mismatches and optimize said design, where nano-scale devices potentially have large-scale process variations. The method includes providing a tunable circuit topology, wherein each nano-scale device comprises a single component or comprises multiple parallel components. Each component is decomposed into multiple discrete sub-components, wherein each said sub-component either operates in parallel with other like components to effectively operate like one bigger component. The sub-components are subjected to a dynamic-programming process to adaptively select the sub-components to be kept operational, while configuring the nonselected sub-components to be nonoperational, based on the measurement of at least one operational parameter.

US Patent:

20070019447, Jan 25, 2007

Filed:

Jul 7, 2005

Appl. No.:

11/176055

Inventors:

Gokce Keskin - Pittsburgh PA, US
Xin Li - Pittsburgh PA, US
Lawrence Pileggi - Pittsburgh PA, US

International Classification:

H02H 7/10

US Classification:

363050000

Abstract:

Active resistors for reduction of transient power grid noise. An active resistance added in parallel to the operating circuit blocks of a semiconductor device. This resistance increases the damping ratio of the power grid, which in turn decreases the number and the magnitude of oscillations and/or noise resulting from step disturbances of the power supply current. The active resistance can implemented by a transistor connected to a bias voltage. Alternatively, the active resistance can be implemented by a drive transistor with a gain stage, or two active resistors where one responds to overshoots in the current flow and the second active resistor responds to droops in the current flow.

US Patent:

20230002384, Jan 5, 2023

Filed:

Jun 8, 2022

Appl. No.:

17/835330

Inventors:

- Wilmington, DE
Evan Styduhar - Claymont DE, US
Xin Li - Claymont DE, US
Wenqing Yao - Chadds Ford PA, US

International Classification:

C07D 471/14
A61K 31/506
A61K 45/06
A61K 31/444
A61K 31/5377
C07D 519/00
A61K 31/496
A61K 31/4375
A61P 35/00

Abstract:

The present disclosure relates to tricyclic heterocycles, and pharmaceutical compositions of the same, that are inhibitors of the FGFR enzyme and are useful in the treatment of FGFR-associated diseases such as cancer.