SCSI auto-termination

Vit Novak Vit.Novak at Sun.COM
Wed Mar 5 13:44:01 PST 2008


Formatted message: <A HREF="r0803052_f.htm">HTML-formatted message</A>

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 at t10.org), posted by:
> * John Lohmeyer <lohmeyer at 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 at t10.org), posted by:
>> * "Penokie, George" <George.Penokie at 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 at lsi.com
>>
>>
>> -----Original Message-----
>> From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf Of Schmitz,
>> Bill
>> Sent: Monday, March 03, 2008 2:56 PM
>> To: t10 at t10.org
>> Subject: SCSI auto-termination
>>
>> * From the T10 Reflector (t10 at t10.org), posted by:
>> * "Schmitz, Bill" <Bill.Schmitz at lsi.com>
>> *
>> Anybody recall how auto-termination works or where I can find some
>> information about it?
>>
>>
>> *
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>> *
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>
> --
> John Lohmeyer 		 Email: lohmeyer at t10.org
> LSI Corp.			 Voice: +1-719-533-7560
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>
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