FIBRE CHANNEL - T11

TR-xx-1998 Fibre Channel Tape Rev 1.07 August 7, 1998
8.2 FCP Information Units
From a SCSI Initiator to a SCSI Target, the T1 (CMD/Task Mgmt with SI transferred), and T6 (Write
Data with SI transferred) are required and the T12 (Confirm with SI held) is optional. Devices that implement
linking shall also support the T3 (CMD/Task Mgmt) Information Unit. All other SCSI Initiator
to SCSI Target IUs are prohibited.
From a SCSI Target to a SCSI Initiator, the I1 (FCP_XFER_RDY on Write), I3 (Read Data), I4
(FCP_RSP) are required. Devices that implement SCSI linking shall also support the I5 (FCP_RSP)
Information Unit. All other SCSI Target to SCSI Initiator IUs are prohibited. SCSI Targets shall respond
to Task Management functions using I4. Examples of write and read type operations are
shown in Figure 2.
WRITE CMD
READ CMD
T1
FCP_CMND
T1
FCP_CMND
FCP_XFER_RDY
I1
DATA
T6
T6
Single Sequence
Single Sequence
T12
DATA
DATA
DATA
FCP_XFER_RDY
DATA
DATA
DATA
FCP_RSP
FCP_CONF
(optional)
I1
I4
DATA
DATA
DATA
DATA
DATA
FCP_RSP
FCP_CONF
(optional)
Single or Multiple Sequences
I3
I3
I4
T12
8.2.1 FCP_CMND IU (T1/T3)
Figure 2 — FCP Read/Write IU Examples
The T1/T3 Information Unit shall be a Single-Frame Sequence.
SCSI Targets that report a peripheral device type of Array Controller (hex ’C’) shall conform to the SCC defined
LUN addressing mechanism. Other SCSI Targets shall address the LUNs using the “first level addressing”
field of SCC (reference [9]) with “peripheral device addressing method” (00b) as shown in figure 3, unless
they report a different LUN addressing mechanism in response to a Report LUN command. For example:
Figure 3 — FCP 8-byte LUN
Byte 0 Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7
00 LUN 00 00 00 00 00 00
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