Date: Wed, 05 Mar 2008 13:44:01 -0800
From: Vit Novak <Vit.Novak@Sun.COM>
Subject: Re: SCSI auto-termination
To: John Lohmeyer <lohmeyer@t10.org>
Cc: "Penokie, George" <George.Penokie@lsi.com>,
        "Schmitz, Bill" <Bill.Schmitz@lsi.com>, T10 Reflector <t10@t10.org>,
        Vit Novak <Vit.Novak@Sun.COM>
X-Message-Number: 8574
Formatted message: HTML-formatted message

Bill,
I've done a lot of auto-termination in the past based on the principle 
described so aptly by John Lohmeyer below. Any parallel SCSI  device, 
8-bit narrow, 16-bit or 32-bit wide, single ended or LVD, can sense if 
it is the last device on the SCSI bus/chain by testing any  dedicated 
ground pin whether it is grounded or floating. It better  be the OUT	
:-)   pin.  
vit-
John Lohmeyer wrote:
> * From the T10 Reflector (t10@t10.org), posted by:
> * John Lohmeyer <lohmeyer@t10.org>
> *
> Bill and George,
>
> There was also a non-standard auto-termination scheme that some host
adapters used to detect whether both its internal connector and external
connector were connected to external termination. If both were terminated,
the HBA would disable its own termination. This scheme depended on there
being only one HBA. On each connector, the HBA sensed whether one of the
ground lines was actually grounded or floating. This scheme would also work
with LVD.
>
> John
>
> At 3/4/2008 01:00 PM, Penokie, George wrote:
>   
>> * From the T10 Reflector (t10@t10.org), posted by:
>> * "Penokie, George" <George.Penokie@lsi.com>
>> *
>> Bill,
>>
>> I can only assume you are referring to the LVD/MSE multimode termination
>> that was last defined in the SPI-4 standard as we never defined anything
>> else that could be called auto-termination. To find information on that
>> you need to get a copy of SPI-4 and look in section 7.4.1 LVD/MSE
>> multimode termination.
>>
>>
>> Bye for now, 
>> George Penokie
>>
>> LSI Corporation 
>> 3033 41st St. NW 
>> Suite 100 
>> Rochester, MN 55901
>>
>> 507-328-9017 
>> george.penokie@lsi.com
>>
>>
>> -----Original Message-----
>> From: owner-t10@t10.org [mailto:owner-t10@t10.org] On Behalf Of Schmitz,
>> Bill
>> Sent: Monday, March 03, 2008 2:56 PM
>> To: t10@t10.org
>> Subject: SCSI auto-termination
>>
>> * From the T10 Reflector (t10@t10.org), posted by:
>> * "Schmitz, Bill" <Bill.Schmitz@lsi.com>
>> *
>> Anybody recall how auto-termination works or where I can find some
>> information about it?
>>
>>
>> *
>> * For T10 Reflector information, send a message with
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>>
>> *
>> * For T10 Reflector information, send a message with
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>>     
>
> --
> John Lohmeyer 		 Email: lohmeyer@t10.org
> LSI Corp.			 Voice: +1-719-533-7560
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>
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