7.7. E-Tile Transceivers May Fail To Configure
- You have made the PRESERVE_UNUSED_XCVR_CHANNEL assignment to an entire unused E-tile.
- Your design does not provide a reference clock to this unused E-tile.
The reference clock is necessary to generate a pseudo-random data signal to prevent the transceiver from degrading over time. You must instantiate at least one dummy channel in the E-tile using the Native PHY IP GUI. Provide this channel at least one reference clock. All preserved channels in a single E-tile can use the same reference clock.
When your design uses some channels in an E-tile, you can use the per-pin PRESERVE_UNUSED_XCVR_CHANNEL QSF assignment to preserve only the channels in the E-tile that you intend to use. If you never intend to use a channel, you should not add the per-pin PRESERVE_UNUSED_XCVR_CHANNEL QSF assignment.
Here are some examples of PRESERVE_UNUSED_XCVR_CHANNEL QSF assignments.
#Global QSF assignment set_global_assignment -name PRESERVE_UNUSED_XCVR_CHANNEL ON #Per-pin QSF assignment set_instance_assignment -name PRESERVE_UNUSED_XCVR_CHANNEL ON -to AA75