Clock adjustment holdover
AssigneeMellanox Technologies, Ltd.
InventorsWojciech Wasko, Dotan David Levi, Natan Manevich, Maciek Machnikowski
Life of this patent
Estimating the term…
Abstract
In one embodiment, a clock synchronization system includes clock circuitry to maintain a clock running at a clock frequency, a clock controller, and a processor to execute software to generate clock update commands and provide the clock update commands to the clock controller, wherein the clock controller is configured to apply the clock update commands to the clock, store a holdover frequency command to maintain the clock during a failure of the clock update commands, apply the holdover frequency command to the clock responsively to detecting the failure.
Claims22
A clock synchronization system, comprising:
- clock circuitry to maintain a clock running at a clock frequency;
- a clock controller;
- and
- a processor to execute software to generate clock update commands and provide the clock update commands to the clock controller, wherein the clock controller is configured to:
- apply the clock update commands to the clock;
- store a holdover frequency command to maintain the clock during a failure of the clock update commands;
- apply the holdover frequency command to the clock responsively to detecting the failure, wherein the clock controller or the software is configured to generate the holdover frequency command responsively to any one or more of the following:
- an average of clock updates;
- a mean of clock updates;
- a median of clock updates;
- and a mode of clock updates;
- and
- apply the holdover frequency command to the clock in the absence of the clock controller receiving any clock update command within a time period derived from timing criteria.
A clock synchronization system, comprising:
- clock circuitry to maintain a clock running at a clock frequency;
- a clock controller;
- and
- a processor to execute software to generate clock update commands and provide the clock update commands to the clock controller, wherein the clock controller is configured to:
- apply the clock update commands to the clock;
- store a holdover frequency command to maintain the clock during a failure of the clock update commands;
- apply the holdover frequency command to the clock responsively to detecting the failure, wherein the software is configured to:
- provide a message to the clock controller to cancel the holdover frequency command;
- and provide another holdover frequency command to the clock controller to override the previously provided holdover frequency command;
- and
- apply the holdover frequency command to the clock in the absence of the clock controller receiving any clock update command within a time period derived from timing criteria.
A clock synchronization method, comprising:
- maintaining a clock running at a clock frequency;
- generating clock update commands;
- applying by a clock controller the clock update commands to the clock;
- storing a holdover frequency command to maintain the clock during a failure of the clock update commands;
- and
- applying by the clock controller the holdover frequency command to the clock responsively to detecting the failure, wherein the generating the holdover frequency command includes generating the holdover frequency command responsively to any one or more of the following:
- an average of frequency updates;
- a mean of frequency updates;
- a median of frequency updates;
- and a mode of frequency updates, wherein the applying includes applying the holdover frequency command to the clock in the absence of the clock controller receiving any clock update command within a time period derived from timing criteria.
Dependencies are inferred from the claim text.