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Re: Start checking





Rich,

The RS is capable of performing a preamble check that
byte 0 is in lane 0 and is an S. It then checks that
the next 6 bytes are data (not necessarily 0x55) then
that byte 7 is an SFD. Given this level of check at
the RS, I agree that you don't need to check beyond
the S.

Ben

Rich Taborek wrote:
> 
> Ladies and Gentlemen,
> 
> Clause 48 has a mandate to check packet delimiters per agreement in
> Tampa. Clause 48 currently specifies Start as a single code-group in
> lane 0 but does not check the data bytes in lanes 1 through 3. As editor
> I'm going to leave it like this because I haven't had any comments to
> date on it.
> 
> The other obvious possible check to do is to check lanes 1 through 3 for
> the corresponding preamble bytes.
> 
> If anyone can think of a good reason to change the way it is I'd like to
> hear it. Historically, 1000BASE-X had a similar "hair-trigger" for Start
> so I believe that checking only for Start in lane 0 is adequate.
> 
> --
> 
> Best Regards,
> Rich
> 
> -------------------------------------------------------
> Richard Taborek Sr.                 Phone: 408-845-6102
> Chief Technology Officer             Cell: 408-832-3957
> nSerial Corporation                   Fax: 408-845-6114
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