CAD Automation Module Based On Cell Moving Algorithm For Incremental Placement Timing Optimization
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Date
2012-07
Authors
Kan, Mei War
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Engineering Change Order (ECO) is a process to handle logic changes in circuit
design. In deep sub-micron era, logic change in design happens inevitably. Design changes
are required for numerous reasons. The reasons may be to fix design bugs, meeting design
functionality change due to customer’s requirement or optimize design performance such as
power consumption. An incremental placement that has the capability to handle design
changes efficiently manages to save time and cost. This is why ECO remains one of the most
influential steps in Very Large Scale Integration (VLSI) design. This thesis describes timing
driven incremental placement that uses standard-cell move technique to improve timing of
the layout design. A cell filtering function is added in the incremental placement to enhance
chances of layout design timing improvement. This function finalizes which cells need to be
moved to achieve timing path improvement objective. A Computer Aided Design (CAD)
automation module is developed to integrate the incremental placement. This automation
module serves as a post-placement timing optimization solution that also provides a cells
position adjustment strategy such that no cells overlap occur and ensure no significant
deviation from initial placement. There are fifteen benchmark circuits that have been used to
verify the functionality of the developed CAD automation module. Experimental results
show that this approach can effectively reduce maximum negative slack timing up to 54.18
percent. An average of 5.64 percent timing improvement compare to standard-cell move
technique is recorded and preservation on initial placement characteristic is better. This
shows that the approach can effectively reduce maximum negative slack timing better
compare to standard-cell move technique.
Description
Keywords
CAD automation module based on , cell moving algorithm