REVISITING Inconsistent usage of "assertion and negation" in training pattern section of SPI-4

Evans, Mark Mark_Evans at
Fri Mar 29 08:53:33 PST 2002

* From the T10 Reflector (t10 at, posted by:
* "Evans, Mark" <Mark_Evans at>
Hi Gerry,

As was stated at the last SPI working group meeting in Dallas, the original
wording in the presentation for starting paced transfers when not training
(00-133r3, slide 10) is that P1 is driven "...for a minimum of 16
clocks...".  This would be 8 assertions and 8 negations, or 200 ns.  It is
unfortunate that something was lost in the translation from the presentation
(to which everyone agreed at the time) to the standard.

Protocol for starting paced transfers when not training was not included in
the first revsions of Bruce Leshay's proposal.  There was still discussion
at the time that we might have to train before every paced transfer.  After
that was resolved, Bruce was asked to include protocol for starting a paced
transfers when not training.  This first appeared in revision 2 of Bruce's
presentation.  At the time I asked if I should modify 00-132 (the actual
proposal) to include the revisions that had been made in Bruce's
presentation, and it was agreed that this was not necessary as what was in
Bruce's presentation in this regard would be included in the next SPI-4
draft.  Something was lost in the translation, and no one caught it.

However, what was accepted was "16 clocks", or "8 assertions and 8
negations", or "200 ns".  I'm happy to revisit this in SPI-5, but not for

Please feel free to call or send an email to me with any additional
questions or comments that you may have about this.


Mark Evans
Maxtor Corporation
500 McCarthy Boulevard
Milpitas,  CA  95035  USA
tel: 408-894-5310
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