MMC 4 & 5, Defect Status Descriptor

David Burg dburg at nero.com
Fri Jan 28 06:49:23 PST 2005


* From the T10 Reflector (t10 at t10.org), posted by:
* "David Burg" <dburg at nero.com>
*
Hello MMC authors and users,

I've trouble to understand the difference between 'm' and 'n' in the =
'Defect
Status Descriptor' description (6.8.3.4 Defect Status data =
(Type=3D02h), after
Table 287 =96 Defect Status Descriptor, in MMC 4r05).

The text is:

"The Start LBA field contains the start Logical Block Address of the
certified sector where the following
Defect Status (DS #n bits) starts. The returned Logical Block Address =
shall
be the first sector of a
Block that contains logical blocks specified by the Blocking Factor =
field.
The End LBA field contains the end Logical Block Address of the =
certified
sector where the following
Defect Status (DS #n bits) ends. The returned Logical Block Address =
shall be
the last sector of a
Block that contains logical blocks specified by the Blocking Factor =
field.
The Blocking Factor field shall indicate the number of logical blocks =
per DS
#m bit. In the case of
DVD-RW, this filed shall be set to 16 as an ECC Block.
The First Bit offset field shall indicate the start valid bit number in =
the
byte 10. The lower bits in the
byte 10 are invalid. e.g., if First Bit offset field contains 3, bit 3 =
of
byte 10 has the defect status of the
block that contains the Logical block specified Start LBA field. From =
bit 2
to bit 0 are invalid in this
case.
DS #n bit contains the certification result of the block #m. When DS #n =
bit
is set to 0, indicate that the
block has no defect and is able to read and write the block safely. =
When DS
#n bit is set to 1,
indicates that the block has defect and might not be able to read and =
write
the block safely."

I initially thought #n refers to a DS number in table 287, and that #m =
was
the block number m plus ("Start LBA" offset / Blocking Factor), with #m =
=3D #n
- First Bit Offset. But when I see "The Blocking Factor field shall =
indicate
the number of logical blocks per DS #m bit.", I am confused (DS #m? not =
DS
#n?).

Can someone tell me the meaning of #m and #n in this MMC text?

Best regards,

David Burg

----------------------------------------------------------------
David Burg
Software Development,
InCD and Low Level Drivers Project Leader

Nero AG               phone: +49 (0)7248 911 862 (room line) Internal =
VoIP
-363
Im Stoeckmaedle 18    fax:   +49 (0)7248 928 299
76307 Karlsbad        email: dburg at nero.com
Germany               http://www.nero.com
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