An important phase in the single row routing approach for multilayer printed circuit board routing is the via assignment phase. The via assignment problem, whose objective is to minimize the number of via columns used, is known to be NP-hard even when each net includes at most three vias. In this paper, we develop efficient approximation algorithms for solving this problem. When the size of each net is bounded by three, we present an algorithm which guarantees that the solution generated uses no more than 2OPTC — 1 via columns, and no more than [(4/3)OPTv \ vias, where OPTcand OPTvare the number of via columns and vias in an optimal solution. We then extend our result to the case that the nets have arbitrary sizes. An efficient algorithm is presented which guarantees the solution generated uses no more than [2.5OPTc] via columns and no more than [1.5OPTV] vias in the worst case.
|Original language||English (US)|
|Number of pages||9|
|Journal||IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems|
|State||Published - Nov 1992|
All Science Journal Classification (ASJC) codes
- Computer Graphics and Computer-Aided Design
- Electrical and Electronic Engineering