VLSI/PCB placement with predefined coordinate alignment constraint based on sequence pair

In the system on a chip, some cells should be placed along a predefined coordinate within a relative small region. This constraint comes from the requirement that the data should be ready on the common bus on the same time. In this paper, we study the module placement problem where some modules have the predefined coordinate alignment (PCA) constraint. We give the relations between constrained modules, from which a necessary condition is induced. We develop a polynomial-time algorithm that can guarantee a feasible placement is always obtainable. Our algorithm is implemented and tested on ami33 and ami49. Its effectiveness is supported by the experimental results