RE: Clause 48: Errors after T.
Stephen,
I may need some more explaining on this one. The check_end function that we
have been talking about sits in the PCS receive state diagram. So, any data
that is coming off of the fiber will hit a PCS receive state machine, right?
Whether it's
RS/XGMII <-> XGXS <-> XAUI <-> XGXS <-> 64b/66b PCS <-> PMA/PMD
or
RS/XGMII <-> 8B/10B PCS <-> PMA/PMD
The data will have to hit a receive state machine at some point in time. I
don't understand why it will only work 50% of the time.
Eric
-----Original Message-----
From: owner-stds-802-3-hssg@ieee.org
[mailto:owner-stds-802-3-hssg@ieee.org]On Behalf Of Stephen.Finch@ti.com
Sent: Thursday, March 29, 2001 10:41 AM
To: stds-802-3-hssg@ieee.org
Subject: RE: Clause 48: Errors after T.
I've been following this thread for awhile and I still don't get it.
I understand the "desire" to propogate a XAUI disparity error back into
the packet in those cases where the error was after the T but still
within "striking distance" of the data, i.e., within one XGMII transfer.
The method, as defined in the draft, will do this for 50% of the times
it occurs.
YES, ONLY 50 % OF THE TIME.
The XAUI devices are between the MAC and the PCS. All of the work we
are doing fixes only those errors in the path from MAC -> XAUI -> PCS,
but in the path PCS -> XAUI -> MAC, the same, exact, identical sequence
of events that are detected and handled by the PCS will not be detected
UNLESS THE MAC DETECTS IT.
Now, if the MAC must detect it for the second case, why not let it
detect it for the first case as well, and remove the REDUNDANT LOGIC
from the PCS?
Is there an error in my thought process?
I've been (quietly) against the inclusion of this since I joined
802.3ae, but being a new comer I assumed I was missing something.
Regards,
Stephen Finch