Maintaining a virtual time of day
OwnerVivek Sardainventor
Life of this patent
Estimating the term…
Abstract
Time of day (ToD) registers provide respective virtual ToDs corresponding to the occurrence of edges of input clock signals being supplied to an integrated circuit. The integrated circuit generates a heartbeat clock signal having a frequency higher than a SYNC signal and time stamps the heartbeat clock signal to generate heartbeat time stamps. The heartbeat time stamps are used along with the time stamps of the input clock signals to determine the time of day corresponding to occurrences of edges of the input clock signals.
Claims18
A method for providing time of day values in a network timing system, the method comprising:
- with circuitry of a master timing card of the network timing system, supplying a clock signal to a slave line card of the network timing system and a plurality of master line cards of the network timing system;
- in a first time of day register of the master timing card, storing a first time of day value corresponding to a first edge of an internal clock signal;
- and
- in a second time of day register of the master timing card, storing a second time of day value corresponding to a second edge of an input clock signal.
A line card for maintaining a time of day in a network communication system, the line card comprising:
- time stamp circuitry configured to generate heartbeat time stamps associated with a heartbeat clock signal, to generate a timing signal time stamp of an edge of a timing signal, and to generate a first time stamp and a second time stamp of a synchronization signal, the synchronization signal indicative of when to increase a time of day;
- and
- conversion circuitry configured to generate a conversion factor to convert from an internal time domain to a network time domain using the first time stamp and the second time stamp;
- and
- time of day circuitry configured to generate a first time of day corresponding to the edge of the timing signal in a network time domain, the first time of day being generated using a heartbeat time stamp of the heartbeat time stamps, the timing signal time stamp, and the conversion factor.
A network timing system comprising:
- a slave line card;
- a plurality of master line cards;
- and
- a master timing card communicatively coupled to supply a clock signal to the slave line card and the plurality of master line cards, the master timing card including circuitry configured to generate heartbeat time stamps associated with a heartbeat clock signal, to generate a timing signal time stamp of an edge of a timing signal, to generate a first time stamp and a second time stamp of a synchronization signal, the synchronization signal indicative of when to increase a time of day, to generate a conversion factor to convert from an internal time domain to a network time domain using the first time stamp and the second time stamp, and to generate a first time of day corresponding to the edge of the timing signal in a network time domain, the first time of day being generated using a heartbeat time stamp of the heartbeat time stamps, the timing signal time stamp, and the conversion factor.
Dependencies are inferred from the claim text.