MMC vs Mt.Fuji on FORMAT UNIT command

Harry Ai ai.takaharu at
Fri Jan 10 01:09:02 PST 2003

* From the T10 Reflector (t10 at, posted by:
* Harry Ai <ai.takaharu at>
Hello MMC people and Mt.Fuji people,

We find one inconsistency between MMC standard and Mt.Fuji specification. 
That is the handling of the Number of Blocks field value and Type Dependent 
Parameter field value in FORMAT UNIT command with Format type=00h.

In Mt.Fuji, the value of those fields is limited to the one reported by 
READ FORMAT CAPACITIES command, i.e. the value shall be selected from one 
of the Formattable Capacity Descroptors reported.

But in MMC2, 3 and 4, there is no such a limitation.

According to our servay, we could not find a C/DVD-R/RW drive which 
implemented this limitation. In addition to that, the MMCTest software in 
HCT11.0 of Microsoft specifies those fields other than the value reported 
by Formattable Capacity Descroptors during CD-RW function testing.

On the other hand, DVD-RAM drives implement it.

One of the idea to solve this problem is to change the definition in both 
MMC and Mt.Fuji to that the limitation is applied only to the DVD-RAM disc.

Best Regards,

Takaharu (Harry) Ai
DVD-RAM Category
Panasonic AVC Network Communications
Osaka, Japan
* For T10 Reflector information, send a message with
* 'info t10' (no quotes) in the message body to majordomo at

More information about the T10 mailing list