RE: Clause 48: Errors after T.
Justin,
D2.3 modified the definition of the check_end function to look at the
current ||T|| column as well as the column after ||T|| and push back any
running-disparity error past /T/ to the previous column. This was done to
address a problem raised by Pat Thaler when an error is detected in lanes
following the /T/ in the ||T|| column.
In general however, errors between /S/ and /T/ should not be pushed back,
as this might result in an /E/ code destroying the /S/ or being moved before
the /S/ delimiter.
To be clear, consider the following cases and how the current definition
of check_end would handle them:
{D="data code" I=idle X="a detected running disparity error" E=the error
symbol)
case 1: (RD error in column after ||T||)
lane0 DEX
lane1 DTI
lane2 DII
lane3 DII
case 2: (RD error after /T/ in ||T||)
lane0 DDI
lane1 DTI
lane2 DII
lane3 EXI
case 3: (RD error before /T/ in ||T||)
lane0 DXI (note, the detected "X" should be replaced with an "E" - no
push back)
lane1 DTI
lane2 DII
lane3 DII
clearly case3 could be handled such that the "E" is pushed back to the
previous column, but that's not how check_end is currently worded. Since
an ||S|| should not immediately precede a ||T|| there should be no
significant problem with pushing any RD error anywhere in ||T|| back one
column, if you feel its a big enough issue then by all means fire off a
comment against D3.0 and we can address it in May.
Regards,
Bob Noseworthy
(603) 862-4342
Clause 48 quasi-co-editor
UNH InterOperability Lab
> -----Original Message-----
> From: owner-stds-802-3-hssg@ieee.org
> [mailto:owner-stds-802-3-hssg@ieee.org]On Behalf Of Justin Gaither
> Sent: Monday, March 26, 2001 5:59 PM
> To: 802.3ae
> Subject: Clause 48: Errors after T.
>
>
> Everyone,
> During the Plenary, it was determined that we need to push an error that
> occurs after the /T/ back 1 column so that it is included inside the /S/
> and /T/ delimeters. My question is, can we just push all errors back on
> column, or must we determine if it is in the column following a //T//?
>
> I could not find this in D2.3, where did it get put?
>
> Thanks
>
> --
> Justin Gaither Phone: 512-306-7292 x529
> RocketChips a Division of Xilinx Fax: 512-306-7293
> 500 N. Capital of TX Hwy.
> Bldg 3 email: jgaither@rocketchips.com
> Austin, TX 78746 WWW: www.rocketchips.com