Agilex™ 7 Configuration User Guide

ID 683673
Date 11/04/2024
Public
Document Table of Contents

7.7. E-Tile Transceivers May Fail To Configure

Making the PRESERVE_UNUSED_XCVR_CHANNEL assignment to completely unused E-tile transceivers may cause configuration failures in Agilex™ 7 devices.
The Quartus® Prime Programmer detects an internal error and fails to configure your device under the following conditions:
  • 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