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

Abstract

Advanced devices and emittercoupled circuit techniques are explored for implementing ultra hgh speed computer arithmetic. Redundant encoding of the input daits 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. Emittercoupled MVL is presented including a novel literal circuit. SPICE simulations of AIGaA&aAs 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.

Redundant arithmetic, algorithms and implementations

“…It is very important to build ultrafast arithmetic circuits. Advanced signal processors with clock rates of the order of gigahertz are required for future system applications such as digital microwave receivers, digital signal processors, and digital RF memories [1]. Carry propagation chains are especially detrimental in ultrafast computation, and they can be completely eliminated by means of redundant arithmetic techniques.…”

“…ECL circuits achieve high speed due to the use of non-saturating transistor operation in di!erential (emitter-coupled) transistor pairs. Some researchers explored the application of ECL techniques in the implementation of very fast redundant arithmetic circuits [1,43].…”

“…On one hand, throughputs of the order of few gigaoperations per second are now conventional in large scienti"c vector processors and supercomputers [1]. This kind of performance is usually achieved by means of fast, densely integrated circuit technologies and highly parallel organizations.…”

“…This kind of performance is usually achieved by means of fast, densely integrated circuit technologies and highly parallel organizations. On the other hand, advanced signal processors with clock rates of the order of gigahertz are required for future system applications such as digital microwave receivers [1]. Speed in these processors is usually limited by the latency of their arithmetic units, especially that of multipliers.…”

Overview of nanoelectronic devices

“…Fewer devices are required to implement a given logic function when using such multistate devices rather than two-state MOSFET's. This generates circuitry with a higher density of logic functions per switching device [20], [110], [177]. (Fewer devices per logic function could also imply less heat dissipation per function, which might help these nanoelectronic devices [155].…”