Abstract
We demonstrate noise-induced phase synchronization among simple digital counters, aiming at its practical application to phase synchronization among isolated digital systems (driven by precise clock sources) accepting common noisy pulse sequences. We employ a simple digital up-counter where i) relaxation oscillations in nonlinear analog oscillators are emulated by linear counting and carry overflow in a low-bit digital counter and ii) the counter value, which is equivalent to the phase of the digitally emulated oscillator, is increased by the precise base clocks, as well as by external noisy pulses, and the autonomous increase of the value (by the base clock) is inhibited by the noisy pulses, depending on the phase of the counter at which the pulse is given. Through extensive Verilog simulations, we demonstrate that the proposed digital counters can be synchronized by applying a common noise sequence, even if initial values of both the counters and phases of the counter's base clocks have different values.
