| 摘要 |
One embodiment of the present invention provides a system that creates a layout of a circuit by placing gates at specific locations in a circuit design based upon drive strengths and wireloads of gates in the circuit. The system operates on a gate-level description of the circuit, which includes a specification of gates in the circuit and a specification of a set of interconnections between the gates. From this gate-level description, the system obtains drive strength information for specific gates in the circuit, and uses this drive strength information as a factor in optimizing a placement for the gates in order to meet a set of timing constraints. The system may also use wireload information-in addition to the drive strength information-to place the gates. A variation on the above embodiment subsequently performs a timing-based placement operation to further optimize the drive strength-based placement. Another variation associates weights with drive strengths for individual gates. These weights are fed into a standard placement function, such as a quadratic placement function or a simulated annealing function, to produce a placement for the gates. Thus, the present invention achieves a better placement of gates than a conventional connectivity-based placement system that merely considers the number of connections to a gate.
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