|
马上注册,结交更多好友,享用更多功能,让你轻松玩转社区。
您需要 登录 才可以下载或查看,没有账号?注册
x
Title:
Static timing analysis in VLSI design
Author:
Zhou, Shuo
Acceptance Date:
2006
Series:
UC San Diego Electronic Theses and Dissertations
Degree:
Ph. D., UC San Diego
Abstract:
The increasing complexity of digital designs and the requirement of timing measurements in
various design stages make static timing analysis critical. Each design stage utilizes static timing
analysis to evaluate the system performance, and then optimizes the design accordingly. An
accurate and efficient timing analysis package is crucial for the success of the whole design
process. We studied three important problems in static timing analysis: false paths, multi-cycle
paths, and hierarchical timing analysis. Static timing analysis should deal with false paths and
multi-cycle paths to produce accurate timings. Previous published works focused on dealing with
false paths in static timing analysis. There are several approaches, such as labeling algorithm
and node-splitting approach, using tags to label and eliminate false path timings. A large number
of tags need to be created and propagated. Thus, the efficiency is deteriorated. For hierarchical
timing analysis, timing analysis iteratively performed on flatten circuits suffers from low efficiency
because of increasing design complexity. Inspired by the gap between challenges and current suboptimal
solutions, we proposed three new techniques: 1. A two-direction propagation is proposed
which minimizes the number of tagged false path timings using a biclique covering approach. We
proved that all the non-false paths are covered and all the false paths are removed. A polynomial
heuristic to perform the biclique covering minimization in minimal degree order is also introduced.
2. A framework unified processing false paths and multi-cycle paths is proposed which expands
the tag- based approach for false paths to cover multi-cycle paths. Following the biclique covering
approach for false paths, we devise time shifting for multi-cycle paths to improve the efficiency.
We prove that the unified framework produces accurate timings. 3. An abstract timing model
reduction technique is proposed for hierarchical timing analysis. We introduce an iterative bicliquestar
replacement technique to minimize the abstract timing model, thus improving the efficiency.
Combined the techniques proposed above, we provide an accurate and efficient static timing
analysis package, which can be used in hierarchical design methodology |
|