MMC5r03a: Duplicate text in timeout G3 description

David Burg daviburg at windows.microsoft.com
Mon Jul 31 19:09:52 PDT 2006


Formatted message: <A HREF="r060731b_f.htm">HTML-formatted message</A>

This is confusing:
To adjust application settings for real-time stream recording/playback to
recover from a fatal error, estimation of
the expected time length for the command is necessary. Group 3 timeout is
defined for this purpose. The
Group 3 timeout duration = Group3 time unit × CI(Transfer length / Unit
length) + trace time for requested
sectors where:
1. Group 3 time unit is the maximum time to read or write one sector.
2. Unit length is the number of sectors that may be read or written within
one Group 3 time unit.
3. Trace time is the time to read or write a sector excluding access time and
the read/write time of the first
sector.
The Group 3 time unit shows the maximum time of an operation when the
transfer length field is set to 1 and
when Power state of the Drive is Active state. In the case of DVD-RAM, the
Group 3 time unit value should
include Zone transition time.
The recommended value for Group 3 time unit is 1 to 5 seconds. The
recommended value for Unit length is 256
sectors.
It is recommended that transfer length and verification length are set to
smaller than the Unit length value. If the
host uses transfer length less than the Unit length, the Group 3 timeout
duration is almost the same as the
Group 3 time unit as follows: (in the case of DVD, 256 sectors is only 0.38
second at 1× speed.)
Group 3 timeout duration = Group 3 time unit + trace time for requested
sectors
The Group 3 time unit shall not be changed by a medium change. A Drive may
accept the value changed by
the host.
The value for Unit length is specific to the media type. A Drive should
adjust the Unit length value according to
the mounted media type.
Group 3 timeout duration of Group 3 timeout has following three exceptions.
1. Exception 1: Initial OPC time
2. Exception 2: Synchronize cache time
3. Exception 3: Power state transition time to Active state
The host is able to control the occurrence of these exceptions by commands
(e.g., SEND OPC INFORMATION
command, SYNCHRONIZE CACHE command). The Drive need not treat these
exceptions as errors.
If Group 3 timeout is supported, G3tout bit of VERIFY (10) command shall be
supported.
Group 3 time unit value shows the maximum time of operation when the transfer
length field is set to 1 and
when Power state of the Drive is Active state. In case of DVD-RAM, Group 3
time unit value should include 1
zone transition time.
The recommended value for Group 3 time unit is 1 to 5 seconds. The
recommended value for Unit length is 256
sectors.
It is recommended that transfer length and verification length be smaller
than the Unit length value. If the Host
uses transfer length less than Unit length, the Expected time is similar with
Group 3 time unit. That is, Expected
time = Group3 time unit + trace time for requested blocks.
Which of the two is the text to keep, which is to discard?
Best regards,
David Burg
Research Software Engineering Lead
Tel.: +1 425 707 8769



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