Mixed Height Element Legalization Method for Minimizing Average and Maximum Movement

Abstract

The invention relates to a legalization method of mixed-height units with minimum average and maximum movement, which represents the circuit as a hypergraph model; after setting the direction of the unit, it is aligned to the adjacent and correctly matched power rail row; for multiple row heights The standard unit is preprocessed, and through the analysis and reconstruction of the objective function and constraints, the legalized model of the mixed height standard unit is planned as a mixed integer quadratic programming model; the mixed integer quadratic programming model is converted into a quadratic programming model model; convert the quadratic programming model into the corresponding linear complementary model; solve the linear complementary model with the matrix splitting iterative method based on the modulus; carry out row redistribution and restore standard units with multiple row heights; use linear programming based method and Kuhn‑Munkres algorithm to legalize the smallest mobile unit. The method proposed by the invention optimizes all the units at the same time, which can meet the requirements of the legalization stage of the mixed height standard unit of the current VLSI.

Description

technical field [0001] The invention relates to an automatic technology for legalizing VLSI mixed height standard units, in particular to a method for legalizing mixed height units with minimum average and maximum movement. Background technique [0002] With the increasing complexity of modern circuit designs, standard cells often produce different cell heights based on characteristics such as area, power, and speed. For example, taller cells can give greater driving force and better routability, while requiring greater area and power costs. Conversely, shorter cells have poorer driving force and routability, but require less area and power costs. Therefore, in order to meet various circuit design requirements, circuits of mixed-height standard cells have become more and more popular. Simple standard cells are designed as a single-row-height structure, while complex standard cells are designed as multiple The row height structure. In order to maintain the quality of the e...

AI Technical Summary

Problems solved by technology

[0005] There are two problems in the existing legalization methods of mixed height standard units: (1) they all use heuristic method to legalize the units one by one, and the angle of dealing with the problem is too partial; (2) they lack theoretical basis and cannot be very Good Quality Guaranteed Legalization

(3) The average and maximum cell movement cannot be minimized at the same time, and the quality of the existing global layout is difficult to guarantee

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