Seagate Fibre Channel Interface User Manual
Page 141
Fibre Channel Interface Manual, Rev. D
127
Field definitions (listed alphabetically)
DF_CTL (Data Field Control)
00h
No optional Fibre Channel headers are used.
D_ID (Destination Identifier)
The address of the drive. This value must match the current address of the drive.
F_CTL (Frame Control)
290000h for FCP CMND frames. This indicates the frame is the first sequence of the exchange and last frame of that
sequence. Sequence initiative is also transferred so the drive may respond to the FCP CMND.
OX_ID (Originator Exchange Identifier)
Assigned by the initiator. This value must be unique for all commands issued by this initiator to the drive. If duplicate
OX_IDs are detected by the drive for uncompleted commands from an initiator, an overlap command error will be returned.
Parameter
Not used for the FCP CMND.
R_CTL (Routing Control)
Set to Unsolicited Command data sequence for the FCP CMND frame.
RX_ID (Responder Identifier)
Not used by the drive. FFFFh indicates the RX_ID is not being used.
SEQ_CNT (Sequence Count)
0000h value indicates that this is the first frame of the Fibre Channel sequence. The FCP CMND is a single frame
sequence.
SEQ_ID (Sequence Identifier)
May be set to any value. The OX_ID field uniquely identifies each command between the initiator and the drive.
S_ID (Source Identifier)
The address of the initiator that sent the frame. This address is used by the drive to return any responses that may be
required by the operation.
Type
08h
All SCSI FCP frames must be set to this value.
Table
number