Maxtor Atlas SCSI Drive 15K II, Руководство по эксплуатации продукта

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SCSI Description
5-146 Maxtor Atlas 15K
5.46 WRITE (10) Command (2Ah)
The WRITE (10) command requests that the drive write initiator-supplied data to the
medium. The data format and field descriptions are shown in Table 5-209 and Table
5-210 respectively.
Table 5-209
WRITE (10) Command Descriptor Block-Data Format
Table 5-210
WRITE (10) Command-Field Descriptions
Bit
Byte
7 6 5 4 3 2 1 0
0 Operation Code (2Ah)
1 Reserved DPO FUA Reserved RelAdr
2 - 5 Logical Block Address
6 Reserved
7 - 8 Transfer Length
9 Control
Field Description
DPO
Disable Page Out. When the value of the field is 1, the drive tells the controller to bypass
cache as much as possible. The buffers used for the WRITE data are given a low priority.
This bit may be useful if the host CPU is performing a background copy operation and
does not want to wipe out the drive's cache.
When DPO is 0, the drive tells the controller to cache this WRITE data in a normal man-
ner.
NOTE: The drive normally assigns a low priority to write caching. Therefore, the DPO
bit in a WRITE command is ignored.
FUA
Force Unit Access. When 1, the data must be written on the medium before GOOD status
is returned. When 0, GOOD status may be returned after the data is fetched from the ini-
tiator and before it is written to the medium. If the WCE (Write Cache Enable) bit on the
MODE SELECT command Caching Page is clear, the FUA bit is ignored and behaves as
if it were always set (that is, if WCE = 0, the controller forces FUA = 1).
Logical Block
Address
The address of the first logical block where the Write operation will occur.
RelAdr Relative Address. This drive does not support this feature; the field must be 0.
Transfer Length
The number of contiguous logical blocks of data to write. The drive returns CHECK
CONDITION status with the correct sense data if the specified transfer would cause the
write operation to extend beyond the Logical Block Address space.