The User Guide for the IP states that it is compliant with 3.0.
Stratix® 10 Avalon®-MM Interface for PCI Express* Solutions User Guide
https://docs.altera.com/r/docs/683667/23.4/l-tile-and-h-tile-avalon-memory-mapped-ip-for-pci-express-user-guide/serial-data-interface
(search for PIPE Interface)
(excerpt)
"6.1.6.2. PIPE Interface"
The Stratix 10 PIPE interface compiles with the PHY Interface for the PCI Express
Architecture PCI Express 3.0 specification.
Note, however, that some signals from 4.4.1 and later are also mixed in.
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Category: PCI-Express
Tools: -
Device: Stratix® 10