Obsoleting QAS in SPI-4

Bill Galloway BillG at breatech.com
Tue May 2 17:44:07 PDT 2000


* From the T10 Reflector (t10 at t10.org), posted by:
* "Bill Galloway" <BillG at breatech.com>
*
I do not understand why all SPI-4 devices have to live on the dirty end of the
fairness stick. SPI-4 devices can implement fairness.  The specification does
not require that all devices be QAS to enable it but neither does it provide a
robust solution to prevent non-QAS devices from being locked out by QAS
devices.  There is no solution for fairness between QAS and non-QAS devices.

I do not believe( I do not know for sure) that anyone has shipped a QAS device
because it requires Packetized to be turned on to enable QAS.


Bill Galloway
BREA Technologies, Inc.
P: (281) 530-3063
F: (281) 988-0358
BillG at breatech.com

-----Original Message-----
From: owner-t10 at t10.org [mailto:owner-t10 at t10.org]On Behalf Of Mike
Kosco
Sent: Tuesday, May 02, 2000 6:15 PM
Cc: t10 at t10.org
Subject: Re: Obsoleting QAS in SPI-4


* From the T10 Reflector (t10 at t10.org), posted by:
* Mike Kosco <Mike at MVBuilders.com>
*
If we obsolete QAS in SPI-4, SPI-4 devices will suffer the same fairness
fate as the pre-SPI-3 devices.  All SPI-1, SPI-2 and SPI-4 devices will
have to live on the "dirty" end of the fairness stick.  I don't believe
there is a rule that says all devices on the bus must be QAS in order to
enable it.

I do agree that obsoleting QAS simplifies design and testing.  Has anyone
shipped devices with QAS support?

Regards,
Mike

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