Internal clock monitoring using external clock provided by communication interface

Abstract

An integrated circuit (IC) includes an internal clock source configured to generate an internal clock signal; a communication interface configured to receive an external clock signal from an external clock source and a communication frame signal that signals a communication frame during which data communication between the IC and the external clock source is enabled, wherein the external clock signal and the communication frame signal are received in parallel; and a clock monitoring circuit configured to monitor the internal clock signal based on the external clock signal. The clock monitoring circuit is configured to compare the internal clock signal and the external clock signal during the communication frame, and generate a timing error signal if a frequency of the internal clock signal does not satisfy a predetermined threshold relative to a frequency of the external clock signal.