A coding method for 123 decision diagram pass transistor logic circuit synthesis

Pass transistor logic (PTL) circuits are known for their smaller silicon area usage, low power consumption and reduced delay advantages. The 123 decision diagram is a very effective PTL synthesis tool based on binary decisions. It realizes a logic function using NMOS pass transistors with CMOS restoring buffers. At the same time, layout of the circuit for a two metal process is obtained by this diagram. A special coding is required to apply the 123 decision diagram. Until now, the coding for the diagram has not been explained. In this paper, a very easy and effective coding method for circuit synthesis and simplification with 123 decision diagrams is proposed.