  Many papers have presented multi-valued circuits in various technologies as a
solution to reduce or solve interconnection issues in binary circuits. This
assumption is discussed. While 4-valued signaling could divide by two the
number of interconnects between building blocks, it turns out that circuit
designers use interconnect standards based on differential pairs such as PCIe,
Infiniband, RapidIO, NVLink, etc. Doubling the number of binary signals is a
better solution than using single-ended quaternary signals. The design of
quaternary basic gates, adders and multipliers are compared with the
corresponding binary ones.
  At each level, the transistor count ratio between quaternary and binary
circuits is greater than the x2 information ratio between base 4 and base 2.
Quaternary signaling is not a solution, either between or within circuit blocks .
