MMC-4/6 Reference in SBC-2/3/4
george.penokie at avagotech.com
Wed Sep 10 15:11:49 PDT 2014
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Here is the history.
In the January 2003 CAP meeting is the following information:
5.8 SBC-2 Enhanced Defect Reporting Method (Reflector message 2002/12/18)
Keiji Katata presented a proposal for software-based defect management in
the SBC-2 that would be accomplished
via changes in the Read/Write Error Recovery mode page and the VERIFY(10)
Concerns were raised about duplication of the feature provided by the READ
DEFECT DATA and FORMAT
The group also was confused about whether the proposal intends to modify
SBC-2 or MMC-4. Apparently, coordination
of the two was a concern so that one bit would not end up having different
meanings in the two standards.
The group discussed the mechanics of the proposed changes and whether they
might be applicable to SBC-2.
The group agreed to have SBC-2 mark as restricted the Read/Write Error
Recovery and command bits used by
MMC-4 for this feature. There will be no SBC-2 changes until the MMC-4
group informs this working group exactly
what changes have been approved for MMC-4.
As a result of the above revision 9 of SBC-2 was modified to change the
three items in the minutes.
Revision 09 of SBC-2 also contains the following note in the revision
1.12 Pending proposals
The following proposals are pending:
a) Monitor MMC-4 for additional bits (Keiji Katata (Pioneer) will provide
notice) to mark as restricted.
In revision 13 of SBC-2 all the restricted for MMC-4 that currently are in
SBC showed up. There is no information in any minutes about adding the
additional restricted for MMC-4 entries. The note in the pending proposals
did not change in revision 13 or 14.
In revision 15, which is the revision that went into letter ballot, the
note in the pending proposal is gone with no further comment or explanation.
The reference remained MMC-4 until Revision 15 of SBC-3 at which time it
was changed to MCC-6. There is no comment about that change in any minutes.
So there you go.
Bye for now,
Attn: George Penokie
4109 Manor View Dr NW
Rochester , MN 55901
george.penokie at avagotech.com
On Wed, Sep 10, 2014 at 3:07 PM, Paul Suhler <Paul.Suhler at hgst.com> wrote:
> At this weekâs CAP meeting, we realized that the following command CDBs
> each have a bit marked as âRestricted for MMC-6.â However, **none** of
> these commands appear in MMC-6. These bits are restricted as far back as
> SBC-2, where they are restricted for MMC-4:
> READ(16) byte 14 bit 7
> VERIFY(12) byte 10 bit 7
> VERIFY(16) byte 14 bit 7
> WRITE(16) byte 14 bit 7
> WRITE AND VERIFY(12) byte 10 bit 7
> WRITE AND VERIFY(16) byte 14 bit 7
> There are three SBC commands with a bit restricted for MMC-4/6 that **do**
> appear in MMC-4/6: READ(12), VERIFY(10), and WRITE(12).
> I am working on a proposal for which I would like to use that bit in the
> READ(16) and WRITE(16) commands. I suspect that in SBC-2 the bit was moved
> into the six commands under the incorrect assumption that they would be
> used in MMC-4, and they were simply carried forward in SBC-3 and -4 without
> being checked.
> *If anyone knows why this bit was marked restricted a decade ago, then
> please let me know.*
> *Paul A. Suhler, PhD*
> Research Staff Member
> HGST Research
> *paul.suhler at hgst.com <paul.suhler at hgst.com>*
> o: 949-476-1180 x275448
> m: 949-241-6443
> 3001 Daimler St.
> Santa Ana, CA 92705-5812
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