Mixed-Row Semiconductor Cell Layout with Monte Carlo Legalization
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Solution Overview
Problem
Conventional automatic placement and routing (APR) tools struggle to efficiently legalize integrated circuit layouts with mixed-row heights, leading to increased processing time.
Innovation Solution
A method involving cell version alteration and rearrangement to reduce cell overlap and congestion, utilizing a Monte-Carlo based algorithm to optimize cell placement and legalization in layouts with mixed-row heights.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional APR legalization is used assuming uniform row heights, then the process is simple to implement, but it cannot efficiently legalize mixed-row height designs leading to increased processing time
Solution Approach 1:
The patent applies parameter changes by transitioning from fixed uniform row height parameters to variable row height parameters. The legalization process dynamically adjusts row height parameters based on cell placement requirements, allowing different rows to have different heights. This enables efficient handling of mixed-row height designs while maintaining reasonable processing speeds through parameter-driven adaptation.
Solution Approach 2:
The patent implements dynamics by making the legalization process adaptive rather than static. The algorithm dynamically determines row heights during placement based on cell characteristics and density requirements. This dynamic approach allows the system to optimize for mixed-row height configurations automatically, improving productivity without requiring manual intervention or overly complex predefined rules.
2Productivity
If mixed-row height design is used, then performance and area optimization is improved, but the APR processing time increases
Solution Approach 1:
The patent applies preliminary action by pre-defining a set of available row height parameters and cell version options before the actual placement process. The system prepares multiple cell versions with different height characteristics in advance, allowing the legalization algorithm to quickly select appropriate versions during placement without performing complex calculations in real-time. This reduces processing time while maintaining the benefits of mixed-row height optimization.
Solution Approach 2:
The patent uses parameter changes to switch between different cell versions based on row height requirements. By having pre-characterized cell versions with known height parameters, the system can rapidly adjust parameters during placement to achieve optimal performance and area utilization without the computational overhead of calculating optimal heights from scratch for each placement decision.
3Adaptability or versatility
If cell versions are altered to conform to different row heights, then mixed-row height legalization is enabled, but cell overlap and congestion may increase
Solution Approach 1:
The patent implements feedback mechanisms where the legalization algorithm continuously monitors cell placement status and adjusts subsequent placements based on detected overlaps and congestion. When cell version alterations cause overlapping or congestion issues, the system receives feedback about these violations and modifies the placement strategy accordingly, selecting alternative cell versions or adjusting positions to resolve conflicts while maintaining row height compatibility.
Solution Approach 2:
The patent applies dynamics by making the cell version selection process adaptive rather than static. Instead of committing to fixed cell versions early in the process, the system dynamically selects and switches between different cell versions during legalization based on real-time placement conditions. This dynamic adaptation allows the system to maintain row height compatibility while preventing overlap and congestion through continuous adjustment.
Data Source
AI summary
The present disclosure provides a method and an apparatus for arranging electrical components within a semiconductor device, and a non-transitory computer-readable medium. The method includes (a) placing a plurality of cells in a first layout, wherein the first layout includes a first row and a second row adjacent to the first row; (b) dividing the first layout into a plurality of regions; (c) calculating a first density of each of the plurality of regions; (d) calculating, for a first region of the plurality of regions, a first probability of altering cell versions for cells in the first region according to the first density of the first region; (e) altering cell versions of one or more cells in the first region according to a comparison between the first probability and a first threshold; and (f) rearranging the cells in the first layout to reduce cell overlap.