GMII and AutoNegotiation

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Hello,
If I understand the spec(802.3) correctly , AutoNegotiation is a part of
the PCS layer and works hand in hand with the TenBit Inteface. Is it
possible that I Can have a MAC with a GMII Interface (NO PCS) and still have
AutoNegotiation inside the MAC.
 
G

Guest

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Archived from groups: comp.dcom.lans.ethernet,comp.dcom.sdh-sonet (More info?)

Hello Zanzy....

> If I understand the spec(802.3) correctly , AutoNegotiation is a part
> of the PCS layer and works hand in hand with the TenBit Inteface.

Correct, in fact it is part of the PHY.

> Is it possible that I Can have a MAC with a GMII Interface (NO PCS)
> and still have AutoNegotiation inside the MAC.

If there is no PCS (or PHY), there is no medium to negotiate....
The MAC does not perform Auto-negotiate.

Regards, Huub.

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Archived from groups: comp.dcom.lans.ethernet,comp.dcom.sdh-sonet (More info?)

Huub van Helvoort wrote:
> Hello Zanzy....
>
>> If I understand the spec(802.3) correctly , AutoNegotiation is a part
>> of the PCS layer and works hand in hand with the TenBit Inteface.
>
> Correct, in fact it is part of the PHY.

Actually it doesn't have to be, although it is fairly common. If the
phy has a TBI interface, it doesn't handle the auto negotiation. If it
has an xMII interface, can (and usually does).

>> Is it possible that I Can have a MAC with a GMII Interface (NO PCS)
>> and still have AutoNegotiation inside the MAC.
>
>
> If there is no PCS (or PHY), there is no medium to negotiate....
> The MAC does not perform Auto-negotiate.

Yep - it is the PCS layer that handles the auto negotiation. Some
devices have it, others do not.

Have fun,

Marc