Clock synchronization over a switched fabric

Patent metadata

Field	Value
Publication number	US-9160472-B2
Application number	US-201213606293-A
Country	US
Kind code	B2
Filing date	Sep 7, 2012
Priority date	Sep 7, 2012
Publication date	Oct 13, 2015
Grant date	Oct 13, 2015

Abstract

Devices and methods for synchronizing devices over a switched fabric. A master device maintains a global time, determines a mapping between the global time and a counter of a switch over a memory-mapped fabric, and sends the mapping to a slave device. A slave device maintains a local time, determines a first mapping between the local time and a counter of a switch, receives a second mapping between the counter and a global time of the master device, and synchronizes its local time to the global time based on the first and second mappings. The master and slave device may map their times to the counter by sending respective request packets to the switch and receiving respective completion packets including respective counter values from the switch. The master and slave device may determine respective time values corresponding to the respective counter values based on in-switch delays of the packets.

First claim

We claim:

1. A system, comprising:
a master device, comprising:
a first functional unit; and
at least one first I/O port, coupled to the first functional unit; and

a slave device, comprising:
a second functional unit; and
at least one second I/O port, coupled to the second functional unit;

wherein the first functional unit is configured to:
maintain a global time;
read a first counter value of a counter of a switch coupled to the at least one first I/O port over a…

Assignees

• Chandhoke Sundeep
• Greenstreet Rodney D
• Nat Instr Corp

Inventors

• Chandhoke Sundeep
• Greenstreet Rodney D

Classifications

• H04J3/0673

  Electricity · mapped topic

• G06F1/14

  Physics · mapped topic

• H04J3/0667 Primary

  Electricity · mapped topic

• G05B19/042

  Physics · mapped topic

• H04J3/06

  Electricity · mapped topic