Hitachi ULTRASTAR 15K450 HUS154530VLF400 - Manual (Page 73)

Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification
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17.1.6 Exchanges
An Exchange is a set of one or more related non-concurrent sequences that may flow in the same or opposite directions. The
exchange is identified by an Originator Exchange Identifier (OX_ID) and a Responder Exchange Identifier (RX_ID) in the
frame header.
17.2 Basic Link Services
The Basic Link Services are all frames with no payload. The Header TYPE field is set to 00h (Basic Link Service) and R_CTL
is set to 1000xxxxb (Basic Link_Data, Code = xxxx).
Table 28: Basic link service command codes
NOP and RMC are prohibited by the Disk Profile. If the drive receives either an NOP or an RMC, it will ignore it.
Note: PLDA 2.1 specifies: “Reserved FC-PH fields are not required to be checked for zeroes. Validity bits set to 0 remove any
requirement to check the corresponding field for zeroes (e.g., if F_CTL bit 3=0, receiving N_Ports are not required to verify
that the parameter field in word 5 of the frame header contains zeroes).” As such, the drive does not validate 1) reserved FC
fields or 2) fields that are not reserved but are not valid for the current frame (as the example above with F_CTL bit 3). This
does not apply to any reserved field checking and testing within the FCP_CDB. These fields are checked as per ANSI SCSI
requirements.
17.2.1 Abort sequence (ABTS)
Although ABTS is a Fibre Channel Basic Link Service, it is used by SCSI-FCP to implement the Abort Task, Task Manage-
ment function. It may only be used by a SCSI initiator to abort an entire exchange using the Recovery Abort protocol. Refer to
18.4.1, “Abort Task (Implemented as ABTS BLS)” on page 111 for a description of the Recovery Abort Protocol and the
frame payloads.
The response to ABTS is either BA_ACC or BA_RJT.
Command Description Abbr.
0000 No Operation NOP
0001 Abort Sequence ABTS
0010 Remove Connection RMC
0100 Basic Accept BA_ACC
0101 Basic Reject BA_RJT
Others Reserved