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Re: A Question about "Inter Packet Gap and SOP Lane alignment"


Your question is answered in a presentation made at the La Jolla meeting:
"8B/10B Idle Pattern for 12-byte IPG" by
Rich Taborek and Don Alderrou of nSerial,

This proposal modifies the fixed starting /A/K/R/ Idle pattern for all
applications of 8B/10B encoded 4-lane streams was accepted into the set of
baseline proposals along with the core XAUI/XGXS proposal. The specific change
is as follows:

1) No change to EOP column which contains the first 1 to 4 columns of the IPG.
Note that the EOP counts towards IPG.
2) Transmit /A/ or /R/ randomly while maintaining minimum 16 column /A/ spacing.
3) Transmit /R/
4) Transmit /K/, /R/ or /A/ randomly while maintaining minimum 16 column /A/
spacing until SOP detected. 

Note that this proposal works for IPGs as small as 9. Detailed state machines
are included at the end of the PDF file.

Best Regards,

Boaz Shahar wrote:
> Hello Steve,
> I have a question in regards to your presentation "Inter Packet Gap..." in
> the last meeting:
> You suggest to use only 2 columns of Idle as a minimum for IPG. In previous
> proposals (e.g.
> slide 14) the suggested gap is a minimum of 3 columns-/A/, /K/, and /R/. So:
> Can you please say which of them should be eliminated, or define a procedure
> which say which type of Idle columns should be inserted?
> Thanks,
> Boaz
Richard Taborek Sr.                 Phone: 408-845-6102       
Chief Technology Officer             Cell: 408-832-3957
nSerial Corporation                   Fax: 408-845-6114
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Santa Clara, CA 95054