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Altera_Forum
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13 years ago

Ethernet autonegotiation

I am just wondering what kind of procedures are running during the link establishment in 100Base-T ethernet in case auto negotiation is disabled (i.e. forced mode) at both ends of the ethernet con...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

Yes, I think that's what I said, the MAC has to be configured (one way or another) for duplex, via the driver polling the phy to get autoneg results, or manual control. I'm not a 10Mbps expert (most of my knowledge is 1G+), but NLPs (or link test pulses) are "idle" in 10Mbps, so yes, they are still sent in 10Mbps mode. In 100Mbps, FLPs are sent if aneg is enabled (until completion of the aneg process), otherwise it's MLT3 encoded idle.

At higher speeds the mac interface is different, i.e. gmii or xgmii, etc.