Patent ID: 8841974
Filing Date: 2014-09-23
Classification: G01R,H03K

Abstract:
1. An apparatus comprising at least one ring oscillator structure, the ring oscillator structure comprising: a ring oscillator having an inverter chain with an odd number of inverters connected serially, the ring oscillator operable to produce an oscillatory output responsive to receiving an oscillatory input; and a test structure coupled to the ring oscillator and configured to validate producing of an intended oscillating frequency of the oscillatory output within a specified jitter limit by the ring oscillator based on an observability chain input or a test input received at the test structure and oscillatory output received as a feedback signal from the ring oscillator, the observability chain input representing a signal for observing faults associated with enabling or disabling the feedback signal to the ring oscillator, the test input representing an input signal with the intended oscillating frequency.