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REQUIRED [= 04-02]" is reported as sense data. When the IDD receives the
START command, it enters the Active_Wait state.
The IDD enters the Active_Wait state after the power is turned on. When the
spindle motor reaches the state of steady rotation with NOTIFY for the first
time after the power is turned on, the IDD reads the "System Information"
from the system space on the disk drive and initializes each type of control
information. ("System information" includes such information as information
on MODE SELECT parameters and disk media defects). When this
operation is completed, the IDD enters the Active state.
If, at this time, the system information fails to be read or the initialization of
the disk medium (formatting) does not end normally for some reason, data on
the medium cannot be accessed even when the IDD enters the Active state.
•
Commands that can be executed even in the Not Ready state
When the IDD receives any of the following commands, the IDD executes the
command even in the Not Ready state:
•
START/STOP UNIT command
•
RESERVE or RESERVE EXTENDED command
•
RELEASE or RELEASE EXTENDED command
•
WRITE BUFFER command
•
READ BUFFER command
•
INQUIRY command
•
REQUEST SENSE command
When the IDD is in the sense data holding state and the REQUEST SENSE
command is executed normally, the IDD sends the sense data held at this time to
the INIT. When the IDD is not in the sense data holding state, the IDD sends
sense data corresponding to the state of the IDD at this time to the INIT.
•
Operation when formatting is not completed normally
While the FORMAT UNIT command is not being executed following a change of
parameters related to data format using the MODE SELECT command, or when
the operation terminates abnormally for some reason (for example, the power
going off or a HARD RESET) during FORMAT UNIT command execution, the
data on the disk medium cannot be accessed normally. In this case, the IDD
responds to disk media access commands with the CHECK CONDITION status.
The sense data generated in the former case shows MEDIUM ERROR [= 3]/Medium
format corrupted [= 31-00], and in the latter case, MEDIUM ERROR [= 3]/FORMAT
command failed [= 31-01]. In both cases, the IDD is restored to a usable condition by
using the FORMAT UNIT command and initializing the disk medium.
C141-C009
2.6 Power Condition
2-13
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