A Request to MMC WG from BDA

Bill McFerrin billmc37 at ctesc.net
Mon Jan 12 07:33:19 PST 2009


* From the T10 Reflector (t10 at t10.org), posted by:
* Bill McFerrin <billmc37 at ctesc.net>
*
Thank you,
We shall put this on our agenda.
Kind Regards,
Bill McFerrin
keiji_katata at post.pioneer.co.jp wrote:
> Dear Bill,
>
> BDA has a request to MMC6.
>
> For Current/Maximum Capacity Descriptor of the READ FORMAT CAPACITIES
command
> there are two implementations on BD-R drive with a Blank BD-R disc. The 1st
> implementation reports Data Area size as Spare Area included that is
specified
> by BD-R specification. The reported value includes Inner Spare Area that
host
> never be able to Read/Write. The 2nd implementation reports User Data Area
size
> that does not include the Inner Spare Area.
>
> MMC5-BSR+INCITES=430.pdf on page 471
> Table 468 ? Current/Maximum Capacity Descriptor for Unformatted or Blank
Media
> BD-R: The number of sectors in all the data zones on the media.
>
> MMC5 used a term "data zone" for two meanings. The 1st meaning is Data Zone
of
> BD-RE/R that includes user data recordable area and spare area. The 2nd
meaning
> is user data recordable area. These two usages allow these different
> implementations of BD-R drives.
> On the other hand MMC3/MMC4 specifies generic definition of Current/Maximum
> Capacity Descriptor of the READ FORMAT CAPACITIES command as follows;
>
> mmc3r10g.pdf Table 210 on page 201
> 01b Unformatted Media.
> The reported value is for the maximum formatted capacity for this media.
For
> DDCD/CD-RW medium, the value reported is the maximum possible when using
Format
> Type 10h.
>
> mmc4r05a.pdf Table 416 on page 347
> 01b Unformatted Media.
> The reported value is for the maximum formatted capacity for this media.
>
> These two descriptions said that the original intention of this field
requests
> to show the possible maximum recordable / readable capacity of a disc.
> Fortunately Data Zone of CD/DVD does not include Spare Area. Then capacity
of
> all Data Zones of CD/DVD disc follows the original intention.
>
> BDA concluded that two different implementations do not cause any trouble
and
> both implementations are reasonable. Therefore BDA would like to request to
MMC
> WG that MMC6 may have a note that explains these two implementations of the
BD-R
> writable drives as follows.
>
> Note: There are two implementations for BD-R writable drive. One
implementation
> reports a value that includes Inner Spare Area. Another implementation
reports a
> value of the maximum user data recordable area. Host may use the third
> descriptor values of Format Type 32h or READ TRACK INFORMATION Command
response
> to obtain a maximum recordable capacity of the Blank BD-R disc.
>
> I personally think that MMC6 may have same table with Table 210 of MMC3 to
> explain this original intention and then explain each medium definitions.
>
> Best regards,
>
> Keiji Katata
> PIONEER CORP.
>
>
>
>   
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