ABSTRACT
This chapter introduces cost functions and placement processes. Placement involves positioning modules on a workspace with respect to some measures of success while observing specifications and constraints. Good placement configurations meet performance requirements while providing easy and neat pro-ducibility, high reliability, and low cost. Historically, placement techniques have been developed on the basis of minimizing the total wire length on the workspace as the fundamental factor for routability and perceived performance. Because it is impossible to incorporate all of the desired attributes of placement for routability into a coherent mathematical model, a cost function expressing the main routability features is usually employed, often using heuristic methods. Placement algorithms employed in the solution of the placement problem, whether continuous or noncontinuous, fall into two classes: constructive or iterative.
