Seagate Fibre Channel Interface - Manual (Page 332)

318 Fibre Channel Interface Manual, Rev. D
12.55 Verify (12) command
The Verify (12) command requests that the target verify the data written on the medium. This command is
implemented with the disc drive specific parameters listed in Table 218. The drive disconnects while this com-
mand is being executed if the initiator supports disconnect/reconnect.
Field definitions (listed alphabetically)
BytChk (Byte Check)
0
The verification will be a medium verification (CRC, ECC, etc.).
1 A byte-by-byte compare of data on the medium and the data transferred from the initiator. If the compare is unsuc-
cessful, the command terminates with a Check Condition status and the sense key is set to Miscompare.
Control
See Control Bytes in Section 11.2.1.6.
DPO (Disable Page Out)
The DPO bit is used to control replacement of logical blocks in the cache memory when the host has information on the
future usage of the logical blocks.
1
The target assigns the logical blocks accessed by this command the lowest priority for being fetched into or retained
by the cache. The logical blocks accessed by the command are not likely to be accessed again in the near future
and should not be put in the cache memory nor retained by the cache memory.
0 Logical blocks accessed by this command are likely to be accessed again in the near future.
Logical Block Address
The logical block at which the verify operation begins, if RelAdr is zero (0).
RelAdr (Relative Address)
This function is not supported by drives described in this manual.
Table 218: Verify (12) command (AFh)
Bit
Byte
7 6 5 4 3 2 1 0
0 1 0 1 0 1 1 1 1
1 0 0 0 0 0 0
BytChk RelAdr
Reserved DPO
2
Logical Block Address (MSB)
3
Logical Block Address
4
Logical Block Address
5
Logical Block Address (LSB)
6
Verification Length (MSB)
7
Verification Length
8
Verification Length
9
Verification Length (LSB)
10
Reserved
11
Control
AFh
Table
number
218
218
218
218
218