Patent ID: 7487274

Claim:
A system for generating unique TAG IDs for back-to-back TLPs operating in a module within a PCI Express architecture, said system comprising: a Storage Module that stores available TAG IDs and corresponding FLAG bits; a NEXT TAG Module configured to analyze the FLAG bits in the Storage Module; a Prefetch Register that stores a unique TAG ID before it is sent to a selected requesting entity; a FIFO Module having two storage layers such that it may simultaneously store a first TAG ID and a second TAG ID; and a Prefetch Logic Module that is configured to determine whether the FIFO Module is storing a first TAG ID and configured to read the first TAG ID from the FIFO module if the FIFO module is not empty; wherein the NEXT TAG Module is configured to select a next available TAG ID in the Storage Module and write said next available TAG ID to the FIFO Module.