Seagate Fibre Channel Interface User Manual
Page 142
128
Fibre Channel Interface Manual, Rev. D
Field definitions (listed alphabetically)
Abort Task Set
Clears only the queue of commands from the initiator originating the Abort Task Set.
CDB (Command Descriptor Block)
Always 16 bytes long. The actual contents depends on the command type. Unused bytes are not checked by the drive. If
any of the Task Management flags are set in byte 10, the CDB field is ignored.
Clear ACA (Clear Auto Contingent Allegiance)
When this bit is set to one (1) by the initiator that caused the ACA condition, the drive will clear the ACA condition and allow
the drive to resume normal processing of commands.
Clear Task Set
Clears the queue for all initiators. A Unit Attention condition is created for all initiators with commands in the queue other
than the initiator originating the Clear Task Set.
DL (Data Length)
The maximum amount of data (in bytes) to be transferred by the command specified in the CDB.
If the DL value is zero, no data will be transferred regardless of the CDB or Read/Write bits in byte 11.
If the DL value is less than the transfer length in the CDB, the drive will transfer up to the DL value, set the Residual Over
Run bit in the FCP RSP, and place the difference between the actual transfer and DL in the FCP RSP Residual Count field.
If the DL value is greater than the transfer length in the CDB, the drive will transfer the CDB requested length, set the
Residual Under Run bit in the FCP RSP, and place the difference between the actual transfer and DL in the FCP RSP
Residual Count field.
Table 75:
FCP CMND Payload
Bit
Byte
7
6
5
4
3
2
1
0
0
(MSB)
:
Logical Unit Number
7
(LSB)
8
0
0
0
0
0
0
0
0
Reserved
9
0
0
0
0
0
Task Attribute
Reserved
10
Term Task
Clear ACA
Target
Reset
0 0
Reserved
Clear Task
Set
Abort Task
Set
0
Reserved
11
0
0
0
0
0
0
Read Data
Write Data
Reserved
12
(MSB)
:
CDB
27
(LSB)
28
(MSB)
DL
29
30
31
(LSB)
Table
number