According to one embodiment, an information processing device, includes: a digital-to-pulse converter configured to output a pulse signal including a pulse with a pulse length corresponding to a digital input signal; and a bidirectional selective oscillator including a first ring oscillator and a second ring oscillator, the first ring oscillator including a plurality of delay elements connected in a ring shape in a first direction, the second ring oscillator including a plurality of delay elements connected in a ring shape in a second direction reverse to the first direction. The bidirectional selective oscillator is configured to select one of the first ring oscillator and the second ring oscillator depending on a sign of the digital input signal, oscillate the selected ring oscillator during a period when the pulse is outputted, and keep a state of oscillation operation when the pulse stops being outputted.