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Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification
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18.2.1 FCP_CMNDThe FCP_CMND IU carries either a SCSI command to be executed or a Task Management function to be performed.
Table 89:FCP_CMND payload
18.2.1.1 FCP_LUN
The FCP_LUN field identifies the logical unit number within the Target. The drive is a single LUN with address 0000 0000
0000 0000h.
18.2.1.2 FCP_CNTL
The FCP_CNTL field contains a number of control flags.
Table 90:FCP_CNTL field
The Task Cod es field contains the Task Attributes, as shown in Table91. The Task Attributes are described in 18.3, “Task
Attributes”, on page 109.
Table 91:Task Attribute values
Byte Field Description Size (Bytes)
0
-7
FCP_LUN Logical Unit Number 8
8-11 FCP_CNTL Control Field 4
12
-
27
FCP_CDB SCSI Command Descriptor Block 16
28-31 FCP_DL Data Length 4
Byte Description Size (Bytes)
0 Reserved 1
1 Task Codes 1
2 Task Management function flags 1
3 Execution management codes 1
Value Attribute
xxxx x000b Simple_Q
xxxx x001b Head_of_Q
xxxx x010b Ordered_Q
xxxx x100b ACA_Q (not supported)
xxxx x101b Untagged