Type: Answers


Last Modified: August 09, 2016
Version Found: v16.0
Version Fixed: v16.0
IP Product: PCI Express Gen 3,2 or 1 x8,4,2,1 Hardened IP

Why does the Link Training Status State Machine (LTSSM) for the Arria 10 PCI Express link sometimes go into the Recovery state after initial link training?

Description

The problem can occur due to the transceiver settings for the Arria® 10 PCI® Express IP core are not optimal in Quartus® Prime software versions 16.0 and 16.0.1.  The existing settings may cause bit errors resulting in link Recoveries and Correctable errors for certain channel loss profiles.  These errors are only observed in hardware and not in simulation or during design compilation.

Workaround/Fix

This problem is addressed in the Quartus Prime 16.0.2 software update. See this KDB for recommended settings and/or assignments for PCIe designs in Quartus Prime 16.0.2.