Critical Issue
A CPRI REC master with auto-rate negotation enabled that targets an Arria II GX device may exhibit hold time violations when running at CPRI line rate at or below 2457.6 Mbps.
This issue affects CPRI MegaCore functions in REC configurations with CPRI line rate 614.4, 1228.8, or 2457.6 Mbps and with auto-rate negotiation enabled that target an Arria II GX device.
This issue may cause hold time violations that lead to hardware failure.
To avoid this issue, add the following line to your Quartus II Project Settings File (.qsf):
set_instance_assignment -name GLOBAL_SIGNAL OFF -to
*rx_clkout*
This constraint affects the CPRI MegaCore function PCS rx_clkout
clock.
This issue is fixed in version 12.0 of the CPRI MegaCore function.