Selection Without Atn; Multiple Initiator Environment; Initiator Sense Data; Initiator Mode Select/Mode Sense Parameters - IBM Ultrastar 36LZX Specifications

11.13 Selection without ATN

If the target is selected without ATN signal active, no Identify message is received from the Initiator. In
this case the LUN is identified from the CDB and disconnect permission is disabled. The target does not
perform any phase retries. The target still responds to a subsequent attention condition. However the
LUN is not considered to be known if a fatal error is detected during the Command phase. That is a
Command phase parity error or a fatal message error in response to attention condition during
Command phase is handled as a Bus Free error with no sense data. The target also knows the use of
linked commands if selected without ATN.
Phase retries may be allowed if a subsequent Identify message is received.

11.14 Multiple Initiator Environment

11.14.1 Initiator Sense Data

Separate sense data is reserved for each I-T-L. Each sense data is maintained independent of
commands from other initiators.

11.14.2 Initiator Mode Select/Mode Sense Parameters

A single shared copy of the Mode Select/Mode Sense parameters is maintained by the drive. This
includes both the current and saved parameters.

11.14.3 Initiator Data Transfer Mode Parameter

A separate data transfer mode parameters area is reserved and maintained for each initiator.

11.15 Contingent Allegiance Condition

The contingent allegiance condition shall exist following the return of Check Condition, except for a
Check Condition caused by Invalid LUN. Execution of all queued commands shall be suspended until the
contingent allegiance condition is cleared.
The contingent allegiance condition can be cleared by the initiator in one of the following ways:
Ÿ By issuing a REQUEST SENSE command to the Target and receiving the sense data. This is the
recommended way.
Ÿ By issuing any other command to the I_T_x nexus that reported the fault.
Ÿ By issuing an Abort message to the I_T_x nexus that reported the fault. This will also abort the
current and queued I/O process from that initiator.
Ÿ By issuing a Bus Device Reset message to the Target. This will also abort all current and queued I/O
processes.
Ÿ By generating a RESET condition on the bus. This MUST be the last resort.
Ultrastar 36LZX hard disk drive specifications
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