Digital Logic Using Non-DC Signals

Abstract

In this chapter, a new type of combinational logic circuit realization is presented. These logic circuits are based on non-DC representation of logic values . In this scheme, logic values can be represented by signals that are uncorrelated, for example, distinct values represented by independent stochastic processes (noise from independent sources). This provides a natural way of implementing multivalued logic . Signals driven over long distances could take advantage of this fact and can share interconnect lines. Alternately, sinusoidal signals can be used to represent logic values. Sinusoid signals of different frequencies are uncorrelated. This property of sinusoids can be used to identify a signal without ambiguity. This chapter presents a logic family that uses sinusoidal signals to represent logic 0 and logic 1 values. We present sinusoidal gates which exploit the anti-correlation of sinusoidal signals, as opposed to uncorrelated noise signals. This is achieved by employing a pair of sinusoid signals of the same frequency, but with a phase difference of 180°. Recent research in circuit design has made it possible to harvest sinusoidal signals of the same frequency and 180° phase difference from a single resonant clock ring , in a distributed manner. Another advantage of such a logic family is its immunity from external additive noise. The experiments in this chapter indicate that this paradigm, when used to implement binary valued logic, yields an improvement in switching (dynamic) power.

Based on Bollapalli, K.C.; Khatri, S.P.; Kish, L.B.; “Implementing digital logic with sinusoidal supplies,” Design, Automation & Test in Europe Conference & Exhibition (DATE), 2010, pp. 315–318, 8–12 March 2010 © [2010] IEEE.