Abstract: A circuit measures a time interval between a first event and a second event. One or more activity inputs receive a respective signal indicating the first and second events. For each activity input, a respective high-speed serial receiver includes a sampling circuit and a deserializer. The sampling circuit generates sample bits from sampling the respective signal at active edges of a clock signal. The deserializer converts the sample bits into a sequence of parallel data words. The sample bits undergo a first change in response to the first event and a second change in response to the second event. An arithmetic circuit receives the sequence of parallel data words from the respective high-speed serial receiver. The arithmetic circuit determines a number of the sample bits between the first and second changes in the sequence of parallel data words. The number measures the time interval between the first and second events.