Design of multiple-output networks using time domain multiplexing and shared multi-terminal multiple-valued decision diagrams

This paper presents a design method for multiple-output networks using time domain multiplexing (TDM) and shared multi-terminal multiple-valued decision diagrams (SMTMDDs). SMTMDDs represent multiple-valued multiple-output functions, while TDM systems transmit several signals on a single line. This method reduces: 1) hardware; 2) logic levels; and 3) pins. In the logic design, we use two types of decision diagrams (DDs): shared binary decision diagrams (SBDDs) and SMTMDDs. We propose heuristic algorithms to derive shared multiterminal binary decision diagrams (SMTBDDs) from SBDDs, and SMTMDDs from SMTBDDs. Experimental results show the compactness of SMTMDDs over SBDDs in terms of number of non-terminal nodes, where the nodes for output selection variables are not included in the non-terminal nodes. In the network, each non-terminal node of an SBDD and an SMTMDD is realized by a multiplexer (MUX). We also present upper bounds on the number of nonterminal nodes to realize an n-input m-output function by an SBDD and an SMTMDD. In addition, we compare the proposed TDM realization with the conventional one.