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RE: Management PMA/PMD registers for XAUI


As I said before, most of the bits involved aren't PMA bits. They are PMD.
People seem to want transmitter disable bits and loopback as close to the
bottom of the stack as possible which means in the PMD. The PMD signal
detect bits are also accessed through these registers. The PMA/PMD registers
provide control and observability for the optics. We do not duplicate these
functions higher in the stack. 

We have items such as transmit disable at the lower speeds, but I'm not sure
how often implementations actually use it. Access to the signal detect bits
is very useful for localizing faults and the XGXS bits don't totally replace
them. If the XGXS sync bit indicates a lane is bad, the fault may be across
the media or across the XAUI. If the corresponding signal detect bit is
okay, then the fault is probably across the XAUI and if the bit is bad, then
the fault is across the media. Activating loopback in the PMD also can be
used for fault localization as it tests operation in both directions across
the XAUI. 


-----Original Message-----
From: Boaz Shahar [mailto:boazs@xxxxxxxxxxxx]
Sent: Tuesday, April 10, 2001 11:23 AM
To: 'THALER,PAT (A-Roseville,ex1)'; Justin Gaither; 802.3ae
Subject: RE: Management PMA/PMD registers for XAUI

The XGXS layer implements all the functions that are associated with both
the 10GBASE-X PCS and 10GBASE-X PMA defined in clause 48. If in the XGXS
case there is no need for the implementation of the PMA registers (And I
think that there is NO need for that), why it is needed in the case of

> -----Original Message-----
> From: THALER,PAT (A-Roseville,ex1) [mailto:pat_thaler@xxxxxxxxxxx]
> Sent: Tuesday, April 10, 2001 7:58 PM
> To: Justin Gaither; 802.3ae
> Subject: RE: Management PMA/PMD registers for XAUI
> Justin,
> As currently defined, there is only a single PMA in the stack which is
> attached to the PMD. An XGXS doesn't have a separate PMA 
> sublayer. I think
> we should leave it that way. We already fragment the physical 
> layer into a
> lot of sublayers.
> Regards,
> Pat
> -----Original Message-----
> From: Justin Gaither [mailto:jgaither@xxxxxxxxxxxxxxx]
> Sent: Tuesday, April 10, 2001 7:19 AM
> To: 802.3ae
> Subject: Management PMA/PMD registers for XAUI
> When a 10GBase-X PCS is being used as a PHY XGXS, it has a XAUI PMA. 
> Should this PMA have all of the Management registers 
> specified (ie. 1.0,
> 1.1, 1.2&1.3, 1.4, 1.5, 1.8, 1.9)? Or are these registers for the
> PMA/PMD that actually tied to the fiber PMD?  
> Regards,
> justin
> -- 
> Justin Gaither                       Phone: 512-306-7292  x529
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