Interoperation with Retimers Under Marginal Link Quality Conditions in Some Systems
- Description
- In an extremely rare scenario in endpoint applications of the
UltraScale+ architecture,
under marginal link quality conditions in some systems, link training across
retimers at 16 GT/sec with the PCIe4C integrated block, a
cold boot might result in link up failure due to link errors. Note: The support of retimers is limited as described in the Unsupported Features section.
- Workaround
- Where link quality conditions can be characterized and improved at the system level, ensure link quality on both sides of retimer(s) meet or exceed requirements of the governing PCI Express Base Specification and PCI Express Card Electromechanical Specification. In the extremely rare event of link up failure, a follow-on link training attempt should bring the link up; if this workaround is not successful, a second reboot might be required.