Fujitsu MAN3184 Manual Do Utilizador

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C141-E124-01EN
3 - 78
Note:
Even when there is an error in the specification in the CDB, or when a write operation to the
disk media cannot be executed normally due to various other causes, the transfer of data (data
is pre-fetched to the data buffer) from the INIT to the IDD may be executed.  In this case, the
length of data transferred from the INIT to the IDD is undefined.  Also, all the data transferred
to the IDD will not necessarily be actually written to the disk media.  However, if the
command is terminated with a CHECK CONDITION status and the sense key of the sense data
indicates "ILLEGAL REQUEST [=5]," the data from that command is not written to the disk
media by a write operation.
3.2.4
WRITE EXTENDED (2A)
                          Bit
Byte
7
6
5
4
3
2
1
0
0
X‘2A’
1
LUN
u
FUA
0
0
0
2
Logical Block Address (MSB)
3
Logical Block Address
4
Logical Block Address
5
Logical Block Address (LSB)
6
0
0
0
0
0
0
0
0
7
Transfer Block Count (MSB)
8
Transfer Block Count (LSB)
9
0
0
0
0
0
0
Flag
Link
This command transfers the number of blocks of data specified in the "Transfer block count" field
from the INIT and writes them in continuous logical data blocks with the logical data block on the
disk media specified in the "Logical block address" field in the CDB as the top.
The functions of this command are the same as those of the Group 0 WRITE command (Section
3.2.3) with the exception that it is possible to specify 4-byte logical block addresses and 2-byte
transfer block counts.  However, when zero is specified for the "Transfer block count," the
command is terminated normally without pre-fetch being performed.
x  FUA (force unit access)
When this bit is "0", it indicates that the IDD satisfy the command by accessing the cache
memory. For write operations, logical blocks may be transferred directly to the cache memory.
GOOD status may be returned to the INIT prior to writing the logical blocks to the medium.
Any error that occurs after the GOOD status is returned is a deferred error and information
regarding the error is not reported until a subsequent command.