C141-E166 6-3
The IDD does not reply to the SCSI bus for up to 2 seconds after the initial self-diagnostics is
started. After that, the IDD can accept the I/O operation request correctly, but the received
command, except the executable commands under the not ready state (such as INQUIRY,
START/STOP UNIT), is terminated with the CHECK CONDITION status (NOT READY
[=2]/logical unit is in process of becoming ready [=04-01] or logical unit not ready, initializing
command required [=04-02]) during the interval from the spindle motor becomes stable to the IDD
becomes ready. The executable command under the not ready state is executed in parallel with the
initial self-diagnostics, or is queued by the command queuing feature and is executed after
completion of the initial self-diagnostics. When the command that comes under the exception
condition of the command queuing is issued at that time, the IDD posts the BUSY status for the
command. When the error is detected during the initial self-diagnostics, the CHECK
CONDITION status is posted for all commands that were stacked during the initial self-
diagnostics. For the command execution condition, refer to Section 1.4 and Subsection 1.7.4 in
SCSI Logical Interface Specifications.
(2) Online self-diagnostics (SEND DIAGNOSTIC command)
The INIT can make the IDD execute self-diagnostics by issuing the SEND DIAGNOSTIC
command.
The INIT specifies the execution of self-diagnostics by setting 1 for the SelfTest bit on the CDB in the
SEND DIAGNOSTIC command and specifies the test contents with the UnitOfl bit.
When the UnitOfl bit on the CDB is set to 0, the IDD executes the hardware function test only
once. When UnitOfl bit is set to 1, the IDD executes the hardware function test, seek (positioning)
test, and data write/read test for the Internal test space only once.
a. Error recovery during self-diagnostics
During the self-diagnostics specified by the SEND DIAGNOSTIC command, when the
recoverable error is detected during the seek or the write/read test, the IDD performs the error
recovery according to the MODE SELECT parameter value (read/write error recovery
parameter, additional error recovery parameter) which the INIT specifies at the time of issuing
the SEND DIAGNOSTIC command.
PER Operation of self-diagnostics
0 The self-diagnostics continues when the error is recovered. The self-
diagnostics terminates normally so far as the unrecoverable error is not
detected.
1 The self-diagnostics continues when the error is recovered. If the
unrecoverable error is not detected, the consecutive tests are executed till last
test but the self-diagnostics terminates with error. The error information
indicates that of the last recovered error.
b. Reporting result of self-diagnostics and error indication
When all specified self-diagnostics terminate normally, the IDD posts the GOOD status for the
SEND DIAGNOSTIC command.