COUPLED RING OSCILLATOR AND METHOD FOR INITIALIZING THE SAME

摘要

A coupled ring oscillator comprises: q-pieces of ring oscillators (10) each including p-pieces of inverter circuits (11) connected in a ring shape; and a phase coupled ring (20) in which (p × q)-pieces of phase coupled circuits (21) are connected in a ring shape, the phase coupled circuits coupling, in a predetermined phase relationship, one of the outputs of the p-pieces of inverters in one of the q-pieces of ring oscillators with one of the outputs of the p-pieces of inverters in another one of the q-pieces of ring oscillators. In the coupled ring oscillator, one of the p-pieces of inverter circuits in each of the q-pieces of ring oscillators is defined as a set and for at least one set, the outputs of the q-pieces of inverter circuits belonging to this set are locked to the same phase (step-1). Under this condition, the q-pieces of ring oscillators are oscillated (step-2), and then the phase-locked state of the outputs of these inverter circuits is unlocked (step-3).