An approach for variable ordering for PCA-chip2 based on the BDD size

摘要

Plastic Cell Architecture (PCA) is one of extensions of Programmable Logic Devices (PLDs). We have proposed a device PCA-Chip2 and a design automation environment for PCA-Chip2. In the design process, the target function is decomposed into some simple subfunctions and each of them is mapped into the device as a circuit called an object. The size of an object strongly depends on the order of its input variable. The objective of this paper is the reduction of the whole circuit size generated. The order of the input variables is permuted based on the BDD size as a preprocessing of the mapping process and the order of the output variables from an object is permuted for the reduction of the number of the objects. The proposed approach achieves 82% reduction of the total area.