Parametric-Cells Implementation in Expert

Introduction

A parameterized cell (P-Cell) is a cell with user-specified parameters. It is possible to create customized p-cell instances with different composition according to parameter values. Using P-Cells gives a considerable memory reduction in the case of multiple instancing of a cell. Expert layout editor creates temporary ordinary cells for each set of parameter values. All instances of a P-Cell with the same parameter values refer to the same ordinary cell. P-Cells are stored in the Expert database in the form of LISA procedure. Temporary cells are not stored in the database file.

Moreover, P-Cells add enormous flexibility to design and increase designer productivity. The notion of cells allows the designer to avoid repetitive drawing of identical pieces of layout. P-cells provide an additional benefit: a user can quickly introduce changes into the layout by modeling the parameters of an instance of P-Cell rather than redrawing the geometry.