I Stand Corrected

[Mark Evans]

* From the T10 (formerly SCSI) Reflector (t10 at symbios.com), posted by:
* Mark Evans <Mark.Evans at quantum.com>
*
Hello out there,

I agree that the use of the word "de-asserted" is problematic, at best.  I
know we don't always do things exactly alike in T10 and T13, but we did
address this issue in T13.  In the following is the name for each signal
state and its corresponding definition as they are in ATA/ATAPI-4 (I beleive
these are also all consistent with Webster): 

1)	asserted:  a signal is driven by an active circuit to its logical
true state (above ViH if active high and below ViL if active low)
2)	negated:  a signal is driven by an active circuit to its logical
false state (below ViH if active high and above ViL if active low)
3)	released:  a signal is not being driven.  For tri-state drivers,
this means that the driver is in the high impedance state.  For
open-collector drivers, the driver is not asserted.

These definitions are also applied consistently to the double-edge clock
signals DIOR- and DIOW- for Ultra DMA.  When these signal are in the
electrical "low" state they are described as being asserted, and when they
are in the electrical "high" state are described as being negated
(consistent with the original definitions of the signals).

I think the above is a apt solution and one that we should adopt for all T10
documents, as well.  Please feel free to call or send an email to me if you
have any additional questions.

Regards,

Mark Evans
Quantum Corporation
500 McCarthy Boulevard
Milpitas, CA 95035 USA
Tel: 408-894-4019
FAX: 408-952-3620
email: mark.evans at quantum.com  

-----Original Message-----
From:	Richard Moore [SMTP:richard_moore at corp.adaptec.com]
Sent:	Monday, August 31, 1998 5:42 PM
To:	Daniel_F_Smith at notes.seagate.com; T10 Reflector
Subject:	Re: I Stand Corrected

* From the T10 (formerly SCSI) Reflector (t10 at symbios.com), posted by:
* "Richard Moore" <richard_moore at corp.adaptec.com>
*
Thanks for the update. I remember seeing "desertion" somewhere, and it
bothered
me at the time, but I couldn't remember where.

I like "negation" better than "de-assertion" although I have to admit to
a habit of
using "de-assertion" a lot. Technical jargon in a technical context is
not
inherently a bad thing (especially when there's not a standard English
word to
capture a concept) but in this case "negation" just sounds cleaner.

On the other hand, with double-transition clocking, we may need new
terminology since driving the clock signal low is no longer an
"assertion" in
the logical sense. Or maybe we don't need new terms, but we would have
to
define this usage as part of the SCSI jargon.

--
  Richard Moore
  Adaptec Irvine Technology Center


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