Abstract :
Existing three value (0, 1, X,) logic simulators cannot support the use of MOS transmission gates, but this deficiency can be easily eliminated by the addition of one logic value - the high impedance (Z) state. This paper demonstrates that complete transmission gate modeling, including bi-directional operation and Ratio Logic, can be accomplished with this single Z state and explicit node models; and, since four states require the same internal storage as three states, such an enhancement would not require a major software rewrite.
