Due to a problem with the Low Latency 40GBASE-KR4 IP core, link training will fail, rx_pcs_ready will not be asserted, and register 0xB1 will return the value of 0x100. This indicates that the IP core is stuck in Auto-Negotiation mode.
The problem is in hardware only and does not exhibit in simulation. This is a start-up only problem, if rx_pcs_ready asserts the IP Core will continue to work correctly.
Device Family: Intel® Arria® 10, Intel® Arria® 10 GT, Intel® Arria® 10 GX, Intel® Arria® 10 SX
Type: Answers
Area: Intellectual Property
Last Modified: June 15, 2017
Version Found: v14.1
Version Fixed: v16.0 Update 1
Bug ID: FB: 367061;
Why does the LL 40GBASE-KR4 IP Core intermittently fail Auto-Negotiation and thus fails to link up?
Description
Workaround/Fix
The problem is fixed beginning with the Quartus® Prime software version 16.0 update 1.