Abstract: Managing virtual boundaries to enable lock-free concurrent region optimization, including: receiving a model of an integrated circuit (‘IC’); dividing the model into a plurality of regions, wherein none of the plurality of regions overlap with another region; assigning each of the plurality of regions to a thread of execution, wherein each thread of execution utilizes a shared memory space; and optimizing, by each thread in parallel, the assigned region.

Abstract: A method of performing a static timing analysis based on slack values to verify and optimize a logic design includes: selecting one or more circuits within the logic design having at least two inputs taking on a known value; identifying a critical input that controls an output arrival time of the selected circuit from among the inputs that take on the known value; determining one or more non-critical input of the circuit a required arrival time based on the difference between the arrival times of the critical and non-critical inputs; and computing the slack at a critical input based on the difference between the AT of the critical and non-critical inputs. The design optimization based on the slack defined by arrival time differences preferably uses a reverse merge margin design metric. The metric determines the exact required amount of improvement in the input arrival time of non-critical signals of a clock shaping circuit.

Abstract: Spare cells are placed in an IC design by assigning different spare utilization rates to logic cones, applying the rates to corresponding spare cell regions surrounding cells in the cones, identifying any overlap of regions from different logic cones, and inserting a spare cell at the overlapping region having the highest spare utilization rate. The best location for the spare cell is computed using a hypergraph wherein the cells are edges and the regions are nodes. Any node that is dominated by another node is removed and its edge is extended to the dominating node. The spare cell is inserted in the region having the most edges (the edges can be weighted). The process is repeated iteratively, updating the hypergraph by removing nodes connected to spare cell location, and inserting the next spare cell at a region corresponding to the node which then has the greatest number of connected edges.

Abstract: A method of performing a static timing analysis based on slack values to verify and optimize a logic design includes: selecting one or more circuits within the logic design having at least two inputs taking on a known value; identifying a critical input that controls an output arrival time of the selected circuit from among the inputs that take on the known value; determining one or more non-critical input of the circuit a required arrival time based on the difference between the arrival times of the critical and non-critical inputs; and computing the slack at a critical input based on the difference between the AT of the critical and non-critical inputs. The design optimization based on the slack defined by arrival time differences preferably uses a reverse merge margin design metric. The metric determines the exact required amount of improvement in the input arrival time of non-critical signals of a clock shaping circuit.

Abstract: Spare cells are placed in an IC design by assigning different spare utilization rates to logic cones, applying the rates to corresponding spare cell regions surrounding cells in the cones, identifying any overlap of regions from different logic cones, and inserting a spare cell at the overlapping region having the highest spare utilization rate. The best location for the spare cell is computed using a hypergraph wherein the cells are edges and the regions are nodes. Any node that is dominated by another node is removed and its edge is extended to the dominating node. The spare cell is inserted in the region having the most edges (the edges can be weighted). The process is repeated iteratively, updating the hypergraph by removing nodes connected to spare cell location, and inserting the next spare cell at a region corresponding to the node which then has the greatest number of connected edges.

Abstract: An improved solution for designing a circuit is provided. A set of target paths, each of which has a performance attribute that is targeted for improvement, is obtained from a design for the circuit. An influence for one or more of the nodes in the set of target paths is obtained. One or more of the nodes are selected for improvement using the influence. Subsequently, the performance attribute for each selected node is improved. For example, an implementation of the node can be replaced with an implementation having an improved performance attribute. The relative improvement provided by an alternative implementation versus a relative detriment to another performance attribute can be obtained and used in selecting the node(s) for improvement. In one embodiment, the relative improvement and influence are used to obtain a sensitivity metric for each alternative implementation, which is used in selecting the node(s) for improvement. In this manner, the circuit can be improved in a more effective manner.