A high-quality mixed-size analytical placer considering preplaced blocks and density constraints.
Journal
2006 International Conference on Computer-Aided Design, ICCAD 2006, San Jose, CA, USA, November 5-9, 2006
Pages
187-192
Date Issued
2006
Author(s)
Abstract
In addition to wirelength, modern placers need to consider various constraints such as preplaced blocks and density. We propose a high-quality analytical placement algorithm considering wirelength, preplaced blocks, and density based on the log-sum-exp wirelength model proposed by Naylor et al. [20] and the multilevel framework. To handle preplaced blocks, we use a two-stage smoothing technique, Gaussian smoothing followed by level smoothing, to facilitate block spreading during global placement. The density is controlled by white-space re-allocation using partitioning and cut-line shifting during global placement and cell sliding during detailed placement. We further use the conjugate gradient method with dynamic step-size control to speed up the global placement and macro shifting to and better macro positions. Experimental results show that our placer obtains the best published results.
SDGs
Type
conference paper