IBM DCAS-32160 - Ultrastar 2.1 GB Hard Drive, Технические характеристики

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11.1.2.1 Case 1 - Selection message sequence with Inquiry command
The I N Q U I R Y command is a special case in SCSI. It is used to configure the bus when file IDs and LUNs
are not known. The proper response is to return the inquiry data with a peripheral drive type of 1Fh which
indicates that the specified L U N is not supported.
11.1.2.2 Case 2 - Selection message sequence with any other command
Any other commands, except REQUEST SENSE, return C H E C K C O N D I T I O N status when an invalid
L U N is specified in the message sequence following selection.
In response to a REQUEST SENSE
command the target shall return sense data. The sense key shall be set to ILLEGAL REQUEST and the
additional sense code shall be set to LOGICAL U N I T N O T S U P P O R T E D .
11.1.2.3 Case 3 - After selection message sequence
It is permissible for the initiator to issue multiple I D E N T I F Y messages during a single command sequence
provided to L U N remains the same. If the L U N is altered, the file goes to a Bus Free Phase.
11.1.3 Incorrect Initiator Connection
It is an Incorrect Initiator Connection error if any of the following occurs:
an Initiator attempts to establish an I_T_L nexus when an I/O process (either queued or active) with an
I_T_L nexus already exists from a previous connection with the same initiator.
an Initiator attempts to establish an I_T_L_Q nexus when an I_T_L nexus already exists from a pre-
vious connection with the same initiator.
an Initiator attempts to establish an I_T_L nexus when an I_T_L_Q nexus already exists from a pre-
vious connection with the same initiator.
Note: It is not an Incorrect Initiator Connection to send a command without a Queue tag message
when sense is pending on the logical unit for the Initiator that issues the Request Sense command. (If
the command is not Request Sense nor Inquiry, sense data is cleared at receipt of the command. )
an Initiator attempts to establish an I_T_L_Q nexus when an I/O process (either queued or active) with
an I_T_L_Q nexus already exists from a previous connection with the same initiator.
If any of the above errors occur, all queued I/O processes and active I/O processes associated with the
issuing Initiator on the specified logical unit are terminated.
The current I/O process is ended with a
C H E C K C O N D I T I O N status, the sense key is set to A B O R T E D C O M M A N D and the additional sense
code is set to OVERLAP P ED C O M MA N DS A TTEM P TED. Status is only returned for the current I/O
process.
11.1.4 Command Processing During Execution of Active I/O process
When the Target is not executing any active I/O processes, a new I/O process is permitted to execute (unless
execution is prevented by another internal Target condition listed in 11.1.1, “Priority of SCSI Status Byte
Reporting” on page 185).
If an active I/O process does exist when the Target receives a new command, then the Target determines if:
Check Condition Status with Sense Key = Aborted Command is returned for an Overlapped Com-
mands Attempted error
the command is permitted to execute
the command is added to the command queue
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O E M Spec. of DCAS-34330/32160