40GbE 40GBASE-KR4 IP Core Might Not Perform Auto-Negotiation Successfully on Restart

Description

In designs that use the reconfiguration bundle that Altera provides with the 40GbE 40GBASE-KR4 IP core example design, the 40GBASE-KR4 IP core might not operate correctly in auto-negotiation on restart. In the reconfiguration bundle, temperature-based tuning can interfere with the process of reconfiguring the IP core in auto-negotiation mode. As a result, the IP core might not complete auto-negotiation successfully.

This issue only manifests on restart and never in initial power-up.

Resolution

This issue has no workaround. This issue is fixed in version 15.0 Update 1 of the 40-100GbE IP core.