Error (175020): Illegal constraint of LVDS_CHANNEL that is part of Altera LVDS SERDES

Description

You will receive this error if you are using Altera LVDS SERDES IP in Rx-CDR mode, with certain pin constraints in Arria® 10 and Cyclone® 10 GX devices.

The Altera LVDS SERDES IP in Rx-CDR mode may only be placed on dedicated even numbered channels. 

Resolution

To identify which pins may be used in Rx-CDR mode, refer to your device's Dedicated Tx/Rx Channel column of the pinout file. Only pin pairs with even numbers may be used.  For example, LVDS2K_1 may not be used, and LVDS2K_2 can be used.