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RE: 64/66 control code mapping





Roy,

An invitation was mailed to the general reflector to announce this reflector
as soon as it was formed.  Check your emails.

If you do read the coding details you will be able to see that we are NOT
"working to develop a method of keeping 'hari' as part of the requirements
for all of the PHYs".  64b/66b works with the XGMII interface. 8b/10b
"precoding" is not a requirement in any sense.

As you say, it's pretty simple.

- Richard


> -----Original Message-----
> From: Roy Bynum [mailto:rabynum@xxxxxxxxxxx]
> Sent: Sunday, March 12, 2000 8:51 AM
> To: Rick Walker
> Cc: stds-802-3-hssg@xxxxxxxx; 
> stds-802-3-hssg-64B66B@xxxxxxxx; Benjamin
> J. Brown
> Subject: Re: 64/66 control code mapping
> 
> 
> 
> Rick,
> 
> I was unaware that there was a separate ad hoc for the 64B66B 
> encoding.  I
> know that a group of you are working with the 'hari' people 
> to develop a
> method of keeping 'hari' as part of the requirements for all 
> of the PHYs in
> the standard.  I did not know that it had developed into an officially
> sanctioned ad hoc with an officially sanctioned reflector 
> extension.  I was
> unable to get one for the EoS ad hoc when I asked for it.  
> How did you do it
> for something as simple as an encoding scheme?
> 
> Thank you,
> Roy Bynum
> 
> Note:  I am still using this e-mail because I have not been 
> able to get my
> mindspring account active on the reflector yet.
> 
> Rick Walker wrote:
> 
> > Dear Ben,
> >
> > > I've been looking at your 64b/66b presentation and, in
> > > particular, looking at your control code mapping. The
> > > 7-bit line code is specific to encodings from the 8b10b
> > > XAUI interface. This is an optional interface and may
> > > not exist between all MAC and PCS layers. When the XAUI
> > > doesn't exist, what 7-bit line codes should be used?
> >
> > The same linecodes as for XAUI.
> >
> > A 64/66 coder running off of XGMII needs all the logic of a 
> XAUI encoder
> > except for the 8b/10b encoders and serializers.  This logic 
> is required to
> > ensure insertion of Align characters, force SOP to be in 
> lane 1, etc.
> >
> > > Given the protocol stack shown by Brad Booth, I would 
> expect that this
> > > PCS layer be specified to an XGMII and not to an XAUI.
> > > Implementations may choose to short- cut the conversion 
> from XAUI to
> > > XGMII to 64b/66b but the specification should assume it 
> communicates
> > > to the XGMII.
> >
> > XAUI can be thought of as an optional XGMII extender.
> >
> > 64/66 is probably best thought of as optional XAUI physical layer.
> >
> > 64/66 replaces XAUI's 4x3.125Gb/s physical layer with a 
> single 10.3Gb/s
> > serial fiber link.  In the same way, WWDM or parallel fiber 
> solutions
> > can be thought of as optional XAUI physical layers.
> >
> > This may not be consistent with 10GbE's rigorous taxonomy 
> of layers, but
> > I think it is a self-consistent way to describe the situation.
> >
> > If you want to discuss this further, we should probably 
> move to the 64/66b
> > reflector at:
> >
> >     stds-802-3-hssg-64B66B@xxxxxxxx
> >
> > I've replied both to the main hssg reflector and to the 
> 64/66 address.
> > --
> > Rick
>