US 12,273,186 B2
Synchronization of clock domains on a data network
Olaf Mater, Linkenheim-Hochstetten (DE); Lukas Reinbold, Oberkirch-Stadelhofen (DE); Xiongzhi Ning, Karlsruhe (DE); and Steffen Dolling, Ditzingen (DE)
Assigned to Marvell Asia Pte Ltd, Singapore (SG)
Filed by Marvell Asia Pte Ltd, Singapore (SG)
Filed on Feb. 22, 2022, as Appl. No. 17/652,002.
Claims priority of provisional application 63/152,217, filed on Feb. 22, 2021.
Prior Publication US 2022/0271853 A1, Aug. 25, 2022
Int. Cl. H04J 3/06 (2006.01); H04L 7/00 (2006.01)
CPC H04J 3/0658 (2013.01) [H04L 7/0008 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A data network comprising:
a first plurality of nodes operating in a first clock domain based on a first clock source;
a second plurality of nodes operating in a second clock domain based on a second clock source; and
synchronization circuitry accessible to both the first clock domain and the second clock domain without requiring network traffic between the first clock domain and the second clock domain, the synchronization circuitry including time-of-day capture circuitry and drift calculation circuitry, and being configured to periodically calculate a rate of drift between time of day in the respective first and second clock domains; wherein:
each node in one of the first and second clock domains is configured to, when sending a message to a node in another of the first and second clock domains:
calculate a time of day in the another of the first and second clock domains based on an actual time of day in the one of the first and second clock domains and the rate of drift between time of day in the respective first and second clock domains, and
include, in the message to the node in the another of the first and second clock domains, the calculated time of day in the another of the first and second clock domains; and
the data network further comprises:
a plurality of storage locations configured to store previous indications of the time of day as indicated by the first clock source and the second clock source, and previous values of the rate of drift, to provide consistent values of the time of day and the rate of drift during writing of subsequent values of the time of day, and a subsequently calculated rate of drift.