Abstract: A system for using machine-learning to create a model for performing integrated circuit layout extraction is disclosed. The system of the present invention has two main phases: model creation and model application. The model creation phase comprises creating one or more extraction models using machine-learning techniques. First, a complex extraction problem is decomposed into smaller simpler extraction problems. Then, each smaller extraction problem is then analyzed to identify a set of physical parameters that fully define the smaller extraction problem. Next, models are created using machine learning techniques for all of the smaller simpler extraction problems. The machine learning is performed by first creating training data sets composed of the identified parameters from typical examples of the smaller extraction problem and the answers to those example extraction problems as solved using a highly accurate physics-based field solver. The training sets are then used to train the models.

Abstract: Some embodiments provide a method of computing the estimated distance between an external state and a set of states in a multi-state space that represents a region of a design layout. The method identifies a polygon that encloses the set of states. It then identifies vectors to project from the vertices of the polygon based on a model that allows penalizes measurements in certain directions more than other directions. Based on the projected vectors, the method then identifies the estimated distance.

Abstract: Some embodiments of the invention provide a method of specifying a cost function that represents the estimated distance between an external state and a set of states in a multi-state space that represents a region of a design layout. The method identifies a polygon that encloses the set of states. It then identifies vectors to project from the vertices of the polygon. Based on the projected vectors, the method identifies a set of distances that includes the distance between the polygon and each point in a set of points in the external state. The method then uses the identified set of distance to specify the cost function.

Abstract: A method and system for verifying integrated circuit designs through partitioning. In an embodiment, a design is partitioned, then each partition is verified. In one embodiment, the design is partitioned at the granularity of modules. In another embodiment, the design is partitioned at the granularity of instances. In a third embodiment, instances are grouped together, subject to a weight threshold, so as to form possibly overlapping partitions of instances that are contiguous in the design hierarchy, with the purpose of avoiding, to the extent possible, false negatives. In a further embodiment, the design is partitioned to avoid redundant partitions. In an embodiment, model checking is applied to one or more local properties in each partition. In another embodiment, simulation is used to verify each partition.

Abstract: Some embodiments of the invention provide a method of searching for a three-dimensional global path between first and second sets of routable elements in a region of a layout that has multiple layers. The method partitions the region into several sub-regions. It then performs a path search to identify a path between a first set of sub-regions that contains the first-set elements and a second set of sub-regions that contain a second-set element. When the method performing the path search, it explores expansions along Manhattan and non-Manhattan routing directions between the sub-regions on a plurality of layers.

Abstract: Disclosed is a full-chip level verification methodology that combines static timing analysis techniques with dynamic event-driven simulation. The specification discloses a capability to partition a multiple-clock design into various clock domains and surrounding asynchronous regions automatically and to determine the timing of the design on an instance by instance basis. Static timing analysis techniques can be leveraged to verify the synchronous cores of each clock domain. The asynchronous regions of the design and the interaction between synchronous cores of the clock domains are validated using detailed dynamic event-driven simulation without the burden of carrying the interior timing attributes of the synchronous cores that have already been verified.

Abstract: A method and apparatus are provided for solving a set of differential-algebraic equation arising in a circuit simulation is provided. A collocation method is applied to each differential-algebraic equation to discretize the set of differential-algebraic equations. A solution to the set of differential-algebraic equations based on the discretized differential-algebraic equation is then formed.

Abstract: An innovative routing method for an integrated circuit design layout. The layout can include design netlists and library cells. A multiple-level global routing can generate topological wire for each net. An area oriented graph-based detail routing on the design can be performed. A post route optimization after the detail routing can be performed to further improve the routing quality. Some methods can be single threaded all or some of the time, and/or multi-threaded some or all of the time.

Abstract: Some embodiments of the invention provide an integrated-circuit chip that has a design based on a wiring model that allows at least a particular wiring layer to have more than one preferred wiring directions. Other embodiments provide a method of manufacturing an integrated circuit (“IC”) that has a plurality of wiring layers. The method specifies a layout of the IC by using a wiring model that specifies more than one preferred wiring direction for at least a region of a particular wiring layer. The method then uses the layout to fabricate the integrated circuit.

Abstract: Some embodiments of the invention provide a method of decomposing a region of an intergrated circuit (“IC”) layout. The region contains several routable elements. Based on the routable elements, the method defines a plurality of nodes in the region. It then triangulates the region based on the nodes. The method then uses the triangles to define routes in the region.

Abstract: A method and system for testing multiported memories, especially when one or more of the ports are not directly accessible without intervening logic. The method and system segregates the multiported memory into at least two portions which are then used for testing the one or more ports which are not directly accessible.

Abstract: A mechanism is disclosed for recognizing and functionally abstracting a column of memory cells. According to one embodiment, a column of n (where n is an integer greater than 1) memory cells is identified in a description of a circuit. One of the n memory cells is selected as a representative memory cell. Then, the column of n memory cells is represented as a single-memory-cell column comprising the representative memory cell. The column is thereafter functionally abstracted to derive a logic-level representation of the memory cell. After that is done, n?1 additional instances of the logic-level representation are generated. In this manner, the column of n memory cells is functionally abstracted as a column of n logic-level representations of the representative memory cell.

Abstract: An integrated circuit (IC) layout system designs nets for interconnecting cells forming modules of a hierarchical IC design. Each module is defined as having one or more ports through which the nets extend when linking cells forming different modules. The layout system automatically inserts buffers into selected segments of the nets to reduce signal path delays through the nets and assigns the inserted buffers to selected modules. However the layout system inserts buffers only into those net segments for which a buffer insertion would not alter the number of ports any module needs to accommodate the net.

Abstract: A method for connecting Verilog-AMS and VHDL-AMS components in a mixed-language mixed-signal design includes receiving a mixed-language mixed-signal design, where the mixed-language mixed-signal design comprises one or more VHDL-AMS and Verilog-AMS components, including a first VHDL-AMS component and a first Verilog-AMS component. The method further includes receiving a predetermined set of connection rules, resolving incompatibilities between the first VHDL-AMS component and the first Verilog-AMS component in accordance with the predetermined set of connection rules, and connecting the first VHDL-AMS component to the first Verilog-AMS component.

Abstract: To increase the writing speed of masks, context information can be used to distinguish the attributes of portions of the mask that are critical from attributes, and portions, that are less critical. By using this information, which may be derived from the design context of the features, the mask can be written at a higher speed without sacrificing the accuracy of the important attributes or features.

Abstract: A system for adaptive partitioning of circuit components during simulating of a circuit having a hierarchical data structure includes a simulator module having one or more computer programs for 1) selecting a group of leaf circuits from the first branch and the second branch for simulation, where each leaf circuit is represented by a matrix comprising a set of equations, 2) determining a strength of coupling between two or more leaf circuits of the group in accordance with a set of predetermined electrical coupling criteria, 3) if two or more leaf circuits are deemed be strongly coupled, combining the corresponding matrix of each strongly coupled leaf circuit into a combined matrix, and 4) performing computation for the two or more strongly coupled leaf circuits in accordance with the combined matrix. The system adaptively adjusts the group circuit matrix for computing a group of circuits according to the strength of coupling between the circuits.

Abstract: The invention is directed towards method and apparatus that consider diagonal wiring in placement. Some embodiments of the invention are placers that use diagonal lines in calculating the costs of potential placement configurations. For instance, some embodiments estimate the wirelength cost of a placement configuration by (1) identifying, for each net in a net list, a bounding box that encloses all the circuit elements of the net, (2) computing an attribute of each bounding box by using a line that can be completely or partially diagonal, and (3) computing the wirelength cost estimate based on the computed attributes. To estimate the wirelength cost of different placement configurations, other embodiments construct connection graphs that model the net interconnect topologies. These connection graphs can have edges that are completely or partially diagonal. Other embodiments use diagonal lines to measure congestion costs of potential placement configurations.

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: Diffusion effects during an IC fabrication process cause actual dimensions of adjacent conductors in an IC to vary from nominal dimensions specified by data defining the IC layout. A computer-aided design tool processes the layout data to generate a separate database for each layer of the IC, including a separate table corresponding to each grid line of that layer. Each table includes a separate table entry corresponding to each conductor to reside along the table's corresponding grid line, each table entry indicating nominal dimensions and position of its corresponding conductor. The tool sorts grid line tables within each layer's database in an order in which their corresponding grid lines are arranged on that layer, and sorts entries in each table in an order in which their corresponding conductors are to appear along the table's corresponding grid line.

Abstract: Some embodiments of the invention provide a method of decomposing a region of an intergrated circuit (“IC”) layout. The method defines several nodes in the region. The method then specifies a plurality of edges in the region. Each edge is between a pair of nodes, and some edges are neither perpendicular nor parallel to some of the edges. The method uses the edges to define routes in the region.