Heterojunction bipolar technology for emitter-coupled multiple-valued logic in gigahertz adders and multipliers

Abstract

The use of advanced devices and emitter-coupled (EC) circuit techniques for implementing ultra-high-speed computer arithmetic is explored. Redundant encoding of the input digits and multiple-valued operands are used in the positive-digit and signed-digit number systems. Addition in both systems has only three steps and entails no carry propagation chains. Emitter-coupled multivalued logic (MVL) is presented. A novel literal circuit is included. SPICE simulations of AlGaAs/GaAs heterojunction bipolar transistor (HBT) integrated circuits resulted in 1.4-1.6-GHz clock performance estimates of the ECMVL building blocks. Advanced InP-based HBT technology development is proposed to attain 4-10-GHz adder and multiplier performance. Modified circuits using resonant tunneling diodes and transistors are also discussed.<>