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XGMII a/k/r




Hi Brad,

While I don't really sympathize with Mr. Brown's tone, I have
to agree that I can't understand why the a/k/r symbols are sent
over the XGMII.

It looks like a trivial effort to incorporate them into the RS,
but can you explain why they belong there rather than in the XGXS?

Thanks,

Dan Dove
ProCurve Networks Division

>  -----Original Message-----
>  From: Brown, Ben [BAY:NHBED:DS48] [mailto:bebrown@xxxxxxxxxxxxxxxxxx]
>  Sent: Wednesday, April 05, 2000 2:48 PM
>  To: HSSG
>  Subject: Re: Interface reality check
>  
>  
>  
>  
>  Brad,
>  
>  So, now the XGMII has an EMI problem with IDLE? This is the first
>  I've heard of this. This is also the first that I've heard that
>  /a/k/r/ can fix such a problem. It seems purely coincidental that
>  the same pattern used to fix an IDLE EMI problem on XAUI just
>  happens to be the same pattern used to fix an IDLE EMI problem
>  on the XGMII. It sounds like you're trying to find a question to
>  an answer.
>  
>  I must apologize now for the tone of this note. Perhaps this has
>  simply been a bad day but, for the life of me, I can't see where
>  this is coming from or what problem you're hoping to solve.
>  
>  Ben
>  
>  "Booth, Bradley" wrote:
>  > 
>  > Taking Rich's slides that he sent out last Friday, I did a 
>  couple of tweaks.
>  > The concept is that the /A/, /K/ and /R/ that are used for 
>  XAUI are 10-bit
>  > symbols.  We can make them correspond to /a/, /k/ and /r/ 
>  which are their
>  > "byte equivalents."  I put that in quotes, because all 
>  /A/s decode to a
>  > single /a/, all /K/s decode to a single /k/ and all /R/s 
>  decode to a single
>  > /r/.  The reverse is not true; /a/ is not encoded to a 
>  single /A/ (due to
>  > running disparity).  This is the same as in 802.3z.
>  > 
>  > I left the /O/ in, because I think that it might add some 
>  good features in
>  > the future.  But /BL/ and /RF/ got turfed.
>  > 
>  > This format would work for, or could be applied to, all the current
>  > proposals we have on the table from SLP, SUPI, WWDM, WIS, 
>  Serial, MAS/PAM,
>  > etc.  I tried to keep this at an architectural level, not 
>  an implementation
>  > level.  I believe that this architecture should permit the 
>  majority, if not
>  > all, of the implementations that get built.
>  > 
>  > Cheers,
>  > Brad
>  > 
>  >  <<000405_RScoding.pdf>>
>  > 
>  >   
>  -------------------------------------------------------------
>  -----------
>  >                           Name: 000405_RScoding.pdf
>  >    000405_RScoding.pdf    Type: Acrobat (application/pdf)
>  >                       Encoding: base64
>  
>  
>  -- 
>  -----------------------------------------
>  Benjamin Brown
>  Router Products Division
>  Nortel Networks
>  1 Bedford Farms,
>  Kilton Road
>  Bedford, NH 03110
>  603-629-3027 - Work
>  603-624-4382 - Fax
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>