Abstract: A system and method are provided for pessimism reduction of a timing database provided for optimization of a circuit design. Pessimism is reduced through generation of a hybrid graph-based static timing analysis (GBA) and path-based static timing analysis (PBA STA) database. PBA is selectively performed on the most critical GBA identified timing violations with the goal of reducing erroneous pessimism in operational timing characteristics passed on to the physical implementation corrective optimizer module to thereby reduce unnecessary fixing and transformations upon the circuit design to correspondingly reduce design time, temporary storage space, needed processing power for timing closure and to result in a finished operable and tangible circuit device with reduced area, power requirements, and decreased cost.

Abstract: A system and method are provided for common path pessimism removal or reduction (CPPR) in a timing database provided to guide transformative physical optimization/correction of a circuit design for an IC product to remedy operational timing violations detected in the circuit design. Pessimism is reduced through generation of a common path pessimism removal (CPPR) tree structure of branching nodes, and operational timing characteristics of each node. The CPPR tree structure is used to avoid exponential phases propagating in an exploratory manner through the system design, as well as the resultant memory footprint thereof. Additionally, back-tracing node-by-node through the circuit design for each and every launch and capture flip flop pair end point through each possible path thereof is avoided.

Abstract: Disclosed are methods and systems for specifying an analytical wirelength formulation that is continuous along with its derivative. One approach performs a wirelength estimate in which a continuous formulation is employed to identify and use a bounding box to enclose circuit elements of a net, and in which an attribute of the bounding box may be completely or partially diagonal. Such formulations are used for optimizing the wirelength using numerical approaches.

Abstract: Disclosed are methods and systems for specifying an analytical wirelength formulation that is continuous along with its derivative. One approach performs a wirelength estimate in which a continuous formulation is employed to identify and use a bounding box to enclose circuit elements of a net, and in which an attribute of the bounding box may be completely or partially diagonal. Such formulations are used for optimizing the wirelength using numerical approaches.

Abstract: Disclosed are methods and systems for formulating a wirelength estimate that takes into account whether any of the routing directions are unavailable. Under certain circumstances, one or more of the routing layers may not be available for routing a wire. If this occurs, then the bounding box that is determined for performing the wirelength estimate would take into account the unavailability of the layer.

Abstract: Provided are a method, article of manufacture, and apparatus for estimating delays of networks. An automated design system comprises a computer configured to identify a critical path in a network, calculate a delay for the technology-mapped version of the network, calculate a delay for the technology-independent version of the network, calculate a scale factor from the technology-mapped and technology-independent delays, and apply the scale factor to all the delays in the technology-independent network.

Abstract: Provided are a method, article of manufacture, and apparatus for estimating delays of networks. An automated design system comprises a computer configured to identify a critical path in a network, calculate a delay for the technology-mapped version of the network, calculate a delay for the technology-independent version of the network, calculate a scale factor from the technology-mapped and technology-independent delays, and apply the scale factor to all the delays in the technology-independent network.

Abstract: Two time budgeting techniques are provided that are suitable for early and late integrated circuit design phases, respectively. During the early design phase, both the positive and negative slack paths are time budgeted, such that a positive slack path cannot become a negative slack path after budget generation. If all the budget constraints are met by resynthesis for all circuit modules, then the technique guarantees that the final design, when assembled, meets all time constraints. During the late design phase, convergence is guaranteed. Further, synthesis runs for sub-modules focus initially on the worst critical path.

Abstract: Provided are a method, article of manufacture, and apparatus for matching candidate clusters to cells in a technology library. An automated design system comprises a computer configured to use second order signatures in generating candidate permutations of each permutation group in a canonical form of the candidate function. The system selects first and second symmetric subgroups, determines a second order signature for the candidate function and the first and second symmetric subgroups, and compares the second order signature to a corresponding second order signature for a library cell function. If the signatures match, the permutation is continued with the first and second symmetric subgroups being included in an intermediate permutation. If not, the system produces no more intermediate permutations beginning with the first and second symmetric subgroups. Further symmetric subgroups are added to the intermediate permutation.

Abstract: Provided are a method, article of manufacture, and apparatus for identifying candidate clusters for matching to cells in a technology library. An automated design system comprises a computer configured to extract a portion of a circuit, levelize it, select a first node, identify the realizable clusters at the inputs of the first node, and combine the first node with realizable clusters at the inputs to produce candidate clusters. A dummy cluster is used at each input to represent using the input as a fanin. The system takes the cross product of the sets, and the first node is merged with each element of the cross product to produce a set of candidate clusters. The candidate clusters are then checked for realizability by comparing them to cells in the technology library, which includes dummy cells to facilitate mapping to large cells in the technology library. A set of realizable clusters is produced for the first node.