Patent ID: 7675372

Claim:
A method comprising: (a) operating a configurable ring oscillator in a first configuration, wherein the ring oscillator is configurable to have a selectable one of a plurality of signal paths between a first node of the ring oscillator and a second node of the ring oscillator, wherein in the first configuration a first oscillating signal passes from the first node through a first of the signal paths and to the second node; (b) making a first measurement of an operational characteristic of the ring oscillator configured in the first configuration; (c) operating the configurable ring oscillator in a second configuration, wherein in the second configuration a second oscillating signal passes from the first node through a second of the signal paths and to the second node; (d) making a second measurement of the operational characteristic of the ring oscillator configured in the second configuration; (e) using the first and second measurements to determine a circuit simulator parameter and designing a circuit with a circuit simulation tool configured with the circuit simulator parameter.