Importance

Loading Importance Indicators...

Abstract

In PCI-Express and alike communications systems, it is often desirable to keep track of order of arrival into different queues of packets that will later compete for servicing by a downstream resource of limited bandwidth. Use of time stamping to determine order of arrival can be a problem because time of arrival between different packets entering respective ones of plural queues can vary greatly and thus the number of bits consumed for accurately time stamping each packet can become significant. Disclosed are systems and methods for tracking the arrival orders of packets into plural queues by means of travel-along dynamic counts rather than by means of high precision time stamps. A machine system that keeps track of relative arrival orders of data blocks in different ones of plural queues comprises a first count associater that associates with a first data block in a first of the plural queues, a first count of how many earlier arrived and still pending data blocks await in a second of the plural queues; and a count updater that updates the first count in response to one or more of said earlier arrived data blocks departing from the second queue.

Loading the Abstract Image...

First Claim