Critical Issue
Description
Cyclone IV GX transceiver Rx does not support a clock tolerance of /- 500 PPM or /- 1000 PPM.
Resolution
In the ALTGX MegaWizard Plug-In Manager, select a clock tolerance other than /- 500 PPM or /- 1000 PPM in What is the acceptable PPM threshold between the receiver CDR VDO and the receiver input reference clock? on the PLL/Ports tab of the Parameter Settings page.