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Altera_Forum's avatar
Altera_Forum
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10 years ago

PCIE Gen1 and Gen2 negotiation

I've got a board, that sometimes powers up with the BIOS recognising 4 lanes at Gen 2 and sometimes the BIOS only recognises 4 lanes at Gen 1. I'm using a Cyclone 5 CST part, and the hard IP control...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
10 years ago

I've encountered this problem at my previous workplace repeatedly.

For a starter, take a closer look at your AC coupling capacitors, to see if any are either damaged or missing (for a 4x PCIe you should have 8 of those).

Another failure may arise from a damaged connector - the connector must be clean without any signs of scratches.

Report back when you have a chance,

Refael.