Current-mode CMOS latched quaternary threshold logic full adder

A current-mode CMOS circuit that realises the latched quaternary threshold logic full adder function has been realised in standard polysilicon-gate CMOS technology. In its FOLLOW mode, the quaternary full adder accepts two quaternary inputs and a binary CARRY input and develops a two-quaternary-digit output word that is the base-four sum of the inputs. In the HOLD mode, these output states are held by a eight-valued current-mode latch subcircuit. A current-mode CMOS latched quaternary threshold logic full adder circuit is presented and experimental performance described.