134 Product Manual - Disc Drive SCSI-2/SCSI-3 Interface (Vol. 2; Ver. 2), Rev. E
_____________________________________________________________________________________
5.2.1.5
Write Command (0Ah)
Table 5.2.1-10. Write Command
Bit
7
6
5
4
3
2
1
0
Byte(s)
0
0
0
0
0
1
0
1
0
1
Logical Unit No.
[1]
Logical Block Address (MSB)
[2]
0
0
0
2
Logical Block Address
3
Logical Block Address (LSB)
4
Transfer Length
[3]
5
0
0
0
0
0
0 Flag Link [4]
The Write command (Table 5.2.1-10) requests that the disc drive write, to the medium, the data transferred
by the initiator.
Notes.
[1] The LUN must be zero.
[2] The Logical Block Address specifies the logical block at which the write operation shall begin.
[3] The Transfer Length specifies the number of contiguous logical blocks of data to be transferred. A Trans-
fer Length of zero indicates that 256 logical blocks shall be transferred. Any other value indicates the
number of logical blocks that shall be transferred.
[4] See “Control Byte” paragraph 4.2.6.
For systems that support disconnection, the disc drive disconnects when any internal error recovery proce-
dure is required, or the data transfer with the initiator is interrupted for more than 1 millisecond, or if the disc
drive’s internal data buffer is full. After a disconnect the disc drive reconnects depending on the value of the
Buffer Empty Ratio in Page 2 of Mode Select Data (see Section 5.2.1.7).
The initiator must send requested write data to the drive until the drive sends Completion status during a
Status phase or until the initiator Resets/Aborts the command or clears the queue. (Note: the drive may
disconnect and reconnect while executing this command).
Sense Data is valid after this command is executed and Completion status is sent. (refer to the Read Com-
mand description in Section 5.2.1.4).
If the RCD bit is set to zero on the Caching Mode page 08h (cache is enabled), the data that is written by this
command remains in the cache buffer, if no write errors are encountered. This allows a Read command to
access the same data from the cache buffer instead of accessing the media, if the same LBA is requested by
the Read command.
This command is terminated with a Reservation Conflict status and no data is written if any reservation
access conflict (see Section 5.2.1.8) exists.
