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Parameterized Cells

Parameterized cells, or ``pcells'' (or sometimes called ``template cells'') are cells which in addition to possible fixed geometry, contain an executable program that creates geometry according to one or more parameters supplied to the cell. The cell is instantiated for given sets of parameters, so that instances may have layouts that differ. Parameterized cells are often used to represent devices such as MOSFETS that may come in many shapes and flavors. The MOSFET parameters select the size and other properties of each instantiation. As an alternative, in a process design kit one might find hundreds of fixed-cells with different permutations of size and other parameters. A single parameterized cell that replaces the collection of fixed cells can streamline the design process, provide greater flexibility, and reduce errors.

The full and XicII feature sets have support for native and OpenAccess-based portable pcells, as well as the ability to work with the Cadence Virtuoso Express PCellsTM feature. The Xiv feature set, does not support pcells.

There is an ongoing effort to strengthen the parameterized cell capabilities in Xic. The effort includes

The full and XicII feature sets have support for native pcells. The Xiv feature set does not support pcells.

Unfortunately, at the present time legal and financial constraints set by the controlling organization prevent use of OpenAccess in Xic. With OpenAccess, support for portable pcells, and the ability to work with the Cadence Virtuoso Express PCells feature, could be provided. Please contact Whiteley Research if support for OpenAccess would be of use to you. With sufficient demand, the decision to drop OpenAccess support may be revisited.



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Stephen R. Whiteley 2017-03-22