Starting in Quartus® II software version 10.1, output reset signal rc_rx_digitalreset is no longer used and should be left unconnected. Prior to this release, this ouput reset sigal was used as part of the PCI Express® reset structure.
For Quartus II software releases 10.0 and 10.0 SP1, see MegaCore® IP Library Release Notes and Errata for a workaround to a problem with the PCI Express MegaCore function when generating the Gen2 compliance pattern for the hard IP implementation in Stratix® IV GX devices.