In Quartus® II 11.1, transceivers configured in XAUI mode may result in the following Fitter error regarding illegal slew rate settings.
Error: TX PMA element 'altgx_xaui:inst|altgx_xaui_alt4gxb:altgx_xaui_alt4gxb_component|transmit_pma3' has an illegal SLEW_RATE setting off.
Info: "low" is a legal value
Stratix® IV GX, Arria® II GX/GZ and HardCopy® IV devices are affected by this issue.
Manually edit the transmit_pma<>.slew_rate parameter in the ALTGX generated .v file to "low".
This issue will be fixed in the future Quartus II release.