Abstract: The disclosure presents a formulation to support simulatable subset (also known as ‘simple-subset’) of a property specification language. This method is applicable for model checking and simulation. In this formulation, the ‘simple-subset’ is transformed to a set of basic formulas. Verification engines are required to support the basic formula only. The basic formula is a form of automata in the property specification language. This is called SERE implication. The efficiency of verification is dependent on size of automata. Miscellaneous opportunistic rules are applied to optimize SERE implication formulas.
Abstract: A method for particle beam lithography, such as electron beam (EB) lithography, includes predefining a stencil design having a plurality of cell patterns with information from a cell library, fabricating the stencil design, synthesizing a functional description into a logic circuit design after predefining the stencil design so that one or more characteristics of the stencil design are considered during synthesizing of the functional description into the logic circuit design, optimizing the logic circuit design, generating a layout design from the optimized logic circuit design, and forming the logic circuit on a substrate according to the stencil design and the layout design.
Abstract: The various embodiments of the present invention generally relate to systems, methods, and computer program products for placement of at least one cell in a digital integrated circuit layout. A global placement grid of coordinates is formed, where the coordinates represent horizontal and vertical directions. A local placement grid of coordinates is also formed for at least one local region, where the local placement grid of coordinates represent horizontal and vertical directions, and where the at least one local region is adapted to support non-integer multiple height rows. At least one cell is associated with the at least one local region formed, and the cell can be placed in the local placement grid of the local region.
Abstract: A method and system are described to reduce process variation as a result of the semiconductor processing of films in integrated circuit manufacturing processes. The described methods use process variation and electrical impact to modify the design and manufacture of integrated circuits.
Type:
Grant
Filed:
December 6, 2004
Date of Patent:
June 3, 2008
Assignee:
Cadence Design Systems, Inc.
Inventors:
Taber H. Smith, Vikas Mehrotra, David White
Abstract: Some embodiments of the invention provide a method for pre-tabulating sub-networks. This method (1) generates a sub-network that performs a function, (2) generates a parameter based on this function, and (3) stores the sub-network in a storage structure based on the generated parameter. In some embodiments, the generated sub-network has several circuit elements. Also, in some embodiments, the generated sub-network performs a set of two or more functions. Some embodiments store each generated sub-network in an encoded manner. Some embodiments provide a method for producing a circuit description of a design. This method (1) selects a candidate sub-network from the design, (2) identifies an output function performed by the sub-network, (3) based on the identified output function, identifies a replacement sub-network from a storage structure that stores replacement sub-networks, and (4) replaces the selected candidate sub-network with the identified replacement sub-network in certain conditions.
Abstract: Method and system for conducting low-power design explorations are disclosed. The method includes receiving an RTL netlist of a circuit design, creating one or more power requirement files, wherein each power requirement file comprises power commands corresponding to the RTL netlist, generating one or more low-power RTL netlists using the corresponding one or more power requirement files and the RTL netlist, and conducting low-power design explorations using the one or more low-power RTL netlists.
Abstract: Method and system for equivalence checking of a low power design are disclosed. The method includes receiving a register-transfer level (RTL) netlist representation of a circuit, receiving a power specification file for describing power requirements of the circuit, creating a low power gate netlist for representing a design implementation of the circuit using the RTL netlist and the power specification file, creating a reference low power RTL netlist for representing a design specification of the circuit using the RTL netlist and the power specification file, and performing equivalence checking between the low power gate netlist and the reference low power RTL netlist. The method further includes annotating low power information described in the power specification file into the reference low power RTL netlist, and creating low power logic in the reference low power RTL netlist.
Abstract: A method and system are described to reduce process variation as a result of the electrochemical deposition (ECD), also referred to as electrochemical plating (ECP), and chemical mechanical polishing (CMP) processing of films in integrated circuit manufacturing processes. The described methods use process variation and electrical impact to direct the insertion of dummy fill into an integrated circuit.
Type:
Grant
Filed:
September 22, 2004
Date of Patent:
May 27, 2008
Assignee:
Cadence Design Systems, Inc.
Inventors:
Taber H. Smith, Vikas Mehrotra, David White
Abstract: A method and an apparatus to perform logic synthesis preserving high-level specification and to check that a common specification (CS) of two circuits is correct have been disclosed. In one embodiment, the method includes building a circuit N2 that preserves a predefined specification of a circuit N1. In some embodiments, the method includes verifying that N2 and N1 indeed implement the same specification and so they are functionally equivalent.
Abstract: A method and system for particle beam lithography, such as electron beam (EB) lithography, is disclosed. The method and system include selecting one of a plurality of cell patterns from a stencil mask and partially exposing the cell pattern to a particle beam, such as an electron beam, so as to selectively project a portion of the cell pattern on a substrate.
Abstract: A method of particle beam lithography includes selecting at least two cell patterns from a stencil, correcting proximity effect by dose control and by pattern modification for the at least two cell patterns, and writing the at least cell two patterns by one shot of the particle beam after proximity effect correction (PEC).
Abstract: A method and system for lithography simulation is disclosed. The method and system specify a subject region of a lithography image with a CD marker, specify a threshold intensity over the lithography image, specify a gradient to a threshold value of the threshold intensity, and calculate a sensitivity or ratio of change of an image boundary of the lithography image to lithography process variation.
Abstract: A system and method for modeling an IC (integrated circuit) employs a mesh model and a grid model for separating impedance effects between nearby and far-away pairs of mesh elements. Models for relating currents and voltages can be incrementally adapted from other designs or design elements in applications including mixed-signal, analog and RF (radio frequency) circuits.
Type:
Application
Filed:
November 17, 2006
Publication date:
May 22, 2008
Applicant:
Cadence Design Systems, Inc.
Inventors:
Enis A. Dengi, Feng Ling, Ben Song, Warren Harris
Abstract: A method for particle beam lithography, such as electron beam (EB) lithography, includes forming a plurality of cell patterns on a stencil mask and shaping one or more of the cell patterns with a polygonal-shaped contour. A first polygonal-shaped cell pattern is exposed to a particle beam so as to project the first polygonal-shaped cell pattern on a substrate. A second polygonal-shaped cell pattern, having a contour that mates with the contour of the first polygonal-shaped cell pattern, is exposed to the particle beam, such as an electron beam, so as to project the second polygonal-shaped cell pattern adjacent to the first polygonal-shaped cell pattern to thereby form a combined cell with the contour of the first polygonal-shaped cell pattern mated to the contour of the second polygonal-shaped cell pattern. The polygonal-shaped contour of the first and second cell patterns may comprise a rectilinear-shaped contour.
Type:
Application
Filed:
November 21, 2006
Publication date:
May 22, 2008
Applicant:
Cadence Design Systems, Inc.
Inventors:
Akira Fujimura, James Fong, Takashi Mitsuhashi, Shohei Matsushita
Abstract: A system and method for modeling an IC (integrated circuit) employs a mesh model and a grid model for separating impedance effects between nearby and far-away pairs of mesh elements. Models for relating currents and voltages can be incrementally adapted from other designs or design elements in applications including mixed-signal, analog and RF (radio frequency) circuits.
Type:
Application
Filed:
November 17, 2006
Publication date:
May 22, 2008
Applicant:
Cadence Design Systems, Inc.
Inventors:
Enis A. Dengi, Feng Ling, Ben Song, Warren Harris
Abstract: A method of extracting capacitance from a layout record includes imposing voltages on conductors in a layout record, and determining a total charge for each of the conductors to obtain a capacitor element for the conductors. A method of extracting capacitance from a layout record includes matching a configuration of conductors in a layout record against a reference pattern, and determining an extracted capacitance for the conductors based at least in part on the reference pattern. A method of extracting capacitance from a layout record includes providing a layout record of a circuit design, the layout record having data representing conductors and metal fill, and extracting capacitance to determine a set of capacitors between the conductors, the set of capacitors accounting for the metal fill.
Abstract: A system, method, computer program, and article of manufacture for generating a golden circuit including datapath components for equivalence checking of synthesized revised circuit. The method includes generating a set of static, dynamic and derived candidates for the datapath component subcircuit, evaluating the similarity degree for each candidate in relation to the revised circuits and selecting one candidate for implementation in the golden circuit. As a result, the subcircuit of datapath component in the golden circuit is replaced with the subcircuit which is more similar to the revised circuit to improve the efficiency of the equivalence checking.
Type:
Grant
Filed:
November 10, 2005
Date of Patent:
May 13, 2008
Assignee:
Cadence Design Systems, Inc.
Inventors:
Kei-Yong Khoo, Tao Feng, Debjyoti Paul, Chih-Chang Lin
Abstract: Method and system for determining electrical isomorphism between two electrical networks are disclosed. In one embodiment, the method includes representing the circuit as a hierarchically-arranged set of branches. The hierarchically-arranged set of branches including a first branch that includes a first electrical network and a second branch that includes a second electrical network, where the first and second branches are interconnected in the graph through a third branch at a higher hierarchical level in the graph than the first and second branches. Next, the method determines whether the first and second electrical networks are electrically isomorphic networks. If the first and second electrical networks are determined to be electrically isomorphic networks, the first and second electrical networks are represented with a single electrically isomorphic network. The method further includes simulating the first and second electrical networks using the single electrically isomorphic network.
Type:
Grant
Filed:
November 19, 2004
Date of Patent:
May 13, 2008
Assignee:
Cadence Design Systems, Inc
Inventors:
Bruce W. McGaughy, Wai Chung William Au, Baolin Yang
Abstract: The present invention relates to a method and system for tuning a circuit. In one embodiment, the method includes receiving a description of the circuit, and selecting a design point of the circuit for evaluation using a sizing tool, where the design point comprises a design of the circuit that meets a set of predefined design specifications, and the circuit comprises a group of circuit devices. The method further includes receiving a set of tuning information for the group of circuit devices tuning the group of circuit devices using the set of tuning information to create a group of tuned circuit devices, creating an updated layout of the group of tuned circuit devices using a layout tool, creating estimated parasitic information of the group of tuned circuit devices using the updated layout, and verifying the design point meets design goals of the circuit using the estimated parasitic information of the updated layout.
Abstract: Method and system are disclosed for designing a circuit using an integrated sizing, layout, and extractor tool. In one embodiment, a method for designing a circuit including initializing a set of design points, where a design point comprises a design of the circuit that meets a set of predefined design specifications, determining sizes for the circuit using a size optimization iteration process, and pausing the sizing optimization iteration process periodically for updating parasitic information of the circuit. The method further includes selecting a subset of design points from the set of design points, generating a layout of the circuit using devices sizes obtained from the set of design points, generating an extracted netlist using the layout, wherein the extracted netlist includes parasitic information of the circuit, and simulating the circuit using the extracted netlist to verify the set of predefined design specifications are met.