Seagate 77767496 Manual De Usuario
24
Fibre Channel Interface Manual, Rev. D
All frames also have a header and a Cyclic Redundancy Check (CRC) field. The payload data field is optional
(but normally present) with the size and contents determined by the type of frame.
(but normally present) with the size and contents determined by the type of frame.
Figure 8.
Frame structure
6.1.1.1
Start-of-frame (SOF) delimiter
Start-of-frame (SOF) delimiters signal the beginning of a frame. See “Frame delimiters” on page 17. This refer-
enced page contains a list of the various types of SOF delimiters.
enced page contains a list of the various types of SOF delimiters.
6.1.1.2
Frame header
The frame header is 24 bytes long and is present in all frames. It is used to control link operation, control
device protocol transfers, and to detect missing frames or frames that are out of order.
device protocol transfers, and to detect missing frames or frames that are out of order.
Field definitions (listed alphabetically)
DF_CTL (Data Field Control)
Specifies the presence of optional headers in the payload of the frame. The drive does not support optional headers.
00h
Specifies the presence of optional headers in the payload of the frame. The drive does not support optional headers.
00h
The drive sets this field to 00h for all frames it originates (sends), and should also be 00h for all frames sent to the
drive.
drive.
D_ID (Destination Identifier)
The 3-byte N_Port address to which the frame is being sent.
The 3-byte N_Port address to which the frame is being sent.
Table 8:
Frame header format
Byte
Word
Word
0
(bits 31 - 24)
1
(bits 23 - 16)
2
(bits 15 - 08)
3
(bits 07 - 00)
0
R_CTL
D_ID
1
Reserved
S_ID
2
Type
F_CTL
3
SEQ_ID
DF_CTL
SEQ_CNT
4
OX_ID
RX_ID
5
Offset
Bytes
Transmission
Words
4
24
0 to 2112
4
4
24
SOF
Fill
Words
Fill
Words
Frame Header
Payload Data Field
CRC
Fill Bytes
EOF
1
6
0 to 528
1
1
6
Table
number