73 xdwriteread (32) command, Xdwriteread (32) command – Seagate Fibre Channel Interface User Manual
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Fibre Channel Interface Manual, Rev. D
12.73
XDWriteRead (32) command
The XDWriteRead (32) command requests that the target xor the data transferred (data-out) with the data on
the medium and return the resulting xor data (data-in). This is the equivalent to an XDWrite (32) command fol-
lowed by an XDRead (32) command with the same Logical Block Address and Transfer Length. This command
is only available on transport protocols supporting bidirectional commands.
Field definitions (listed alphabetically)
Additional CDB Length
The Additional CDB Length field indicates the number of additional CDB bytes. This value in the Additional CDB Length
field shall be a multiple of 4. If the number of CDB bytes delivered by the service delivery subsystem is not sufficient to con-
tain the number of bytes specified by the Additional CDB Length field, the command shall be terminated with a Check Con-
dition status. The sense key shall be set to Illegal Request and the additional sense code shall be set to Invalid Field in
CDB.
Table 238: XDWriteRead (32) command (7Fh)
Bit
Byte
7
6
5
4
3
2
1
0
0
0
1
1
1
1
1
1
1
1
Control
2
:
6
Reserved
7
Additional CDB Length
8
(MSB)
Service Action (0007h)
9
(LSB)
10
Reserved
DPO
FUA
Disable
Write
Reserved
11
Reserved
12
(MSB)
Logical Block Address
13
14
15
16
17
18
19
(LSB)
20
:
27
Reserved
28
(MSB)
Transfer Length
29
30
31
(LSB)
7Fh
Table
number