A rigorous framework for convergent net weighting schemes in timing-driven placement

We present a rigorous framework that defines a class of net weighting schemes in which unconstrained minimization is successively performed on a weighted objective. We show that, provided certain goals are met in the unconstrained minimization, these net weighting schemes are guaranteed to converge to the optimal solution of the original timingconstrained placement problem. These are the first results that provide conditions under which a net weighting scheme will converge to a timing optimal placement. We then identify several weighting schemes that satisfy the given convergence properties and implement them, with promising results: a modification of the weighting scheme given in [11]results in consistently improved delay over the original, 4% on average, without increase in computation time.

• Type: Journal
• Year: 2009
• Where: ICCAD
• Authors: Tony F. Chan, Jason Cong, Eric Radke
• Keywords: Hardware, ICCAD 2009, Net Weighting Scheme, Timing Optimal Placement, Weighting Scheme