RE: [802.3ae] D3.1 Clause 45 and Clause 48 potential inconsistencies
Ben,
I understand your position about commenting. However, before commenting, I
think I should try to understand the intention there. I'll try to put my
question in a more direct way here, and may will submit another discussion
about the DTE-XS vs. the PHY-XS status definition bits later. So here are
the questions regarding the DTE-XS initially:
Questions
(1) What is the condition for setting bit 5.8.10 ? (p.234) Or: What is the
definition of the event: "The DTE has detected a LF condition on the Receive
path"? Is this the same as: "Has not synchronized and aligned all four
receive lanes"?
AND:
(1.a) If the answer to (1) is "Yes", Do we need the duplication of the same
function on 3 bits: 5.1.2, 5.8.10, and 5.24.12?
(1.b) If the answer to (1) is "No", then what is the exact definition and
how the sentence "A local Fault condition is recognized by the PCS Rx
process whenever align_status=fail" (Clause 48 P. 307) can be explained?
(2) What is the condition for setting 5.8.11 (P.233): Is that user defined?
If not what is the definition of the event: "..the DTE-XS Has detected an LF
condition on the Tx path"
Thx. for your help,
Boaz
> -----Original Message-----
> From: Ben Brown [mailto:bbrown@amcc.com]
> Sent: Friday, July 20, 2001 1:08 AM
> To: Boaz Shahar
> Cc: HSSG (E-mail)
> Subject: Re: [802.3ae] D3.1 Clause 45 and Clause 48 potential
> inconsistencies
>
>
>
>
> Boaz,
>
> Boaz Shahar wrote:
> >
> > Hi there,
> > I would like to clarify certain things regarding LF, RF and
> Link Status:
> >
> > 1.Status bit 5.1.7 suppose to to be set by the transmitter
> if it detects a
> > LF sequence in its input OR set by the receiver if it
> detects LF in its
> > inputs? I think it is NOT set if the receiver detects inter
> lane miss
> > alignment condition (That is, it is not set by the receiver
> if the receiver
> > GENERATES LF as opposed to DETECTING LF). Is that so?
>
> I don't think so. Bit 5.1.7 says it is an "OR" function of bits
> 5.8.11 and 5.8.10. The first sentence of the 5.8.11 definition
> says that this bit "indicates that the DTE XS has detected a
> local fault condition on the transmit path". Also, the RS never
> generates the LF sequence so the DTE XS transmit path can never
> see the LF sequence. The first sentence of the 5.8.10 definition
> says that this bit "indicates that the DTE XS has detected a
> local fault condition on the receive path". I don't see any
> mapping from the local fault conditions in clause 48 to either
> of these bits. This should probably be fixed with a comment of
> some sort.
>
> >
> > 2.The term "DETECT LF" stands for detecting LF sequence in
> the input to a
> > certain function? If a receiver detects miss alignment, and
> generates LF as
> > a result, it is not said to be LF DETECTION event?
>
> I disagree. A receiver that is not in sync or alignment is
> certainly detecting a local fault. The definition for the DTE
> XS transmitter is implementation specific. Recall that transmit
> is in the opposite direction for the PHY XS as it is for the
> DTE XS or the 10GBASE-X PCS.
>
> >
> > 3. Status bit 5.8.11 detects LF on the transmit path of the
> DTE-XS. That is,
> > set by the transmitter when it detects an LF sequence in
> its input in the
> > DTE-XS. Bit 4.8.11 does the same for the PHY_XS. But here,
> transmit path
> > means that the PHY-XS XAUI Receiver has to set this bit.
> So, according to
> > the current definition, depending on this XGXS function,
> PHY-XS or DTE-XS,
> > this bit is set by different modules in any of the cases.
>
> This was what I was trying to say above. However, these bits
> are not set when upon detection of LF sequences, only when the
> data path is not yet operational. When the data path is operational,
> LF sequences are simply forwarded along without any mention to
> management until they get to the RS where they are noted.
>
> >
> > 4.The same is true for bits 5.8.10 vs. 4.8.10
> >
> > It would be better to define:
> >
> > 5.8.11 as Tx path LF Detection for DTE-XS
> > 4.8.11 as Rx path LF Detection for PHY-XS
> > 5.8.10 as Rx path LF Detection for DTE-XS
> > 4.8.10 as Tx path LF Detection for PHY-XS
> >
> > BTW this method works in all other cases of symmetrical
> functionality
> > between PHY-XS and DTE-XS because it saves a MUX in the
> implementation, and
> > more consistent.
>
> This issue has been discussed before and the draft reflects
> how it was settled. If you want to raise the issue again, you'll
> have to submit a comment against the next draft.
>
> Regards,
> Ben
>
> >
> > CLAUSE 48 Question
> > Section 48.2.5.4.1 defines local_fault as follows: "A local
> fault condition
> > is recognized by the PCS whenever align_status=fail". Combining this
> > definition with those in clause 45 can lead to the
> erroneous conclusion that
> > the events "Link Status Fail" and "Local fault detection"
> are identical. So
> > I think it should be changed either in 45 or in 48 (Unless
> this is really
> > the intention).
> >
> > Best regards,
> > Boaz
>
>
> --
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> Benjamin Brown
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