BDD representation for incompletely specified multiple-output logic functions and its applications to functional decomposition

A multiple-output function can be represented by a binary decision diagram for characteristic function (BDD/spl I.bar/for/spl I.bar/CF). This paper presents a new method to represent multiple-output incompletely specified functions using BDD/spl I.bar/for/spl I.bar/CF. An algorithm to reduce the widths of BDD/spl I.bar/for/spl I.bar/CFs is presented. This method is useful for decomposition of incompletely specified multiple-output functions. Experimental results for radix converters, adders and a multiplier show that this method is useful for the synthesis of LUT cascades. This data structure is also useful to three-valued logic simulation.