Question about use of IEEE COMPANY ID in 11-322r2

James C Hatfield james.c.hatfield at
Mon Oct 8 12:09:47 PDT 2012

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T13 has already defined (in ACS-3 rev 4: see A.23.2) that
      bits 31:24 are reserved
      bits 24:0   are the OUI
Thank You !!!
Jim Hatfield
Seagate Technology LLC
   e-mail:  James.C.Hatfield at
   s-mail:  389 Disc Drive;  Longmont, CO 80503 USA
   voice:  720-684-2120
   fax....: 720-684-2711
   cell...: 720-771-8914
On Mon, Oct 8, 2012 at 12:37 PM, Gerry Houlder
<gerry.houlder at>wrote:
> I have noted that 11-322r2 (Device crash dump) has a 32 bit field in the
> returned data for IEEE COMPANY ID. I'm sure this is because the SATA
> equivalent has a 4 byte field for this also. However, the IEEE Company ID
> is a 24 bit value.
> Neither the SATA version or the T10 version of the crash dump feature has
> any guideline about how the 24 bit value is aligned within the 32 bit
> field. There is also the issue of SATA being little endian and SCSI is big
> endian. This could lead to interpretation problems when comparing crash
> dump information from a SATA drive with crash dump information from a SCSI
> drive that are from the same manufacturer (and should have the same company
> ID value).
> I suggest that the 4 byte value should be changed to a 3 byte value plus a
> reserved byte. This would take care of how the 24 bit field is aligned. We
> should also discuss whether we need to require the bytes to be always
> little endian or always big endian regardless of whether the data is from a
> SATA or SCSI drive.

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