An Automated Approach to Generating Leaf Cells for a Macro Cell Configuration
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概要
- 論文の詳細を見る
This paper describes a new automated approach to generating the patterns of CMOS leaf cells from transistor-level connectivity data. This method can generate CMOS leaf cells that are configurable to a macro cell satisfying user-specified constraints. The user-specified constraints include the aspect ratio and port positions of the macro cell. We propose a top-down method for converting the macro cell level constraints to leaf cell level ones. Using this method, a variety of customized macro cells can be designed in a short turn-around time. The method consists of four processes-diffusion sharing, initial placement, placement improvement and routing-which culminate in the automatic generation of symbolic representations. Using a compactor, those symbolic representations can be converted to physical patterns which are gathered into a macro cell by a macro generator. We define various objective functions to improve unit pair placement. We also introduce five ways to optimize leaf cell area: 1) multi-row division, 2) gate division 3) rotation, 4) power line and diffusion overlapping and 5) reconstruction of hierarchical structure. The proposed approach has been applied to various kinds of CMOS leaf cells. Experimental results show that the generated cells have almost the same areas as those generated by conventional bottom-up approaches in leaf and macro cell layouts. This approach offers a further advantage in that the various-sized macro cells required by layout designers can also be generated.
- 社団法人電子情報通信学会の論文
- 1993-08-25
著者
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Watanabe T
Ntt Lsi Laboratories
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Watanabe Takumi
Ntt Lsi Laboratories
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Kusaba Ritsu
NTT LSI Laboratories
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Miyashita Hiroshi
NTT LSI Laboratories
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Miyashita H
Ntt Lsi Lab. Atsugi‐shi Jpn
関連論文
- An Automated Approach to Generating Leaf Cells for a Macro Cell Configuration
- A Preconstrained Compaction Method Applied to Direct Design-Rule Conversion of CMOS Layouts
- Extending Pitchmatching Algorithms to Layouts with Multiple Grid Constraints