Table of Contents
Advertisement
(2)
FC-4 Device Data
Exchanges consist of two or more frame sequences between the initator and the target.
Exchanges starts from command frame by the initiator and ends at response frame by
the target.
Four FC-4 Device Data (FCP_CMND_IU, FCP_XFER_RDY_IU, FCP_DATA_IU,
FCP_RSP_IU) are used to implement SCSI protocol. Figure 1.6 explains the
examples of Exchanges in case of SCSI write/read operation.
a)
SCSI write operation
Initiator
1)
2)
3)
4)
b)
SCSI read operation
Initiator
1)
3)
4)
1)
FCP_CMND_IU
2)
FCP_XFER_RDY_IU ;
3)
FCP_Data_IU
4)
FCP_RSP_IU
Target (drive)
FCP_CMND_IU (WT)
FCP_XFER_RDY_IU
FCP_DATA_IU (Write)
:
FCP_RSP_IU
Target (drive)
FCP_CMND_IU (RD)
FCP_DATA_IU (Read)
:
FCP_RSP_IU
Figure 1.6
Examples of Exchange
;
includes SCSI command and the control information
permits the data transmission from the initiator to the drive
;
Read or Write data between the initiator and the drive
;
Used by the drive to report status/sense data to the initiator
C141-E054-02EN
Exchange ; from command frame to response frame
Exchange ; from command frame to response frame
1 - 9
Advertisement
Table of Contents
