Self-Test Via Send Diagnostic Command - Hitachi HUS151473VL3800 - Ultrastar 73.4 GB Hard Drive Specifications

8. Validation of RAM code and data table (RDM, Log, Mode Page) from the Reserved Area
If Auto spin up is disabled, steps 5 - 8 will be executed by the first START STOP UNIT command which has the Start bit set.
Faults detected before successful completion of the HDC section could prevent the drive from responding to a selection.
Faults detected after the successful completion of the HDC test section will be reported as CHECK CONDITION status to the
Initiator on the first command issued after a fault is detected (except for the INQUIRY, REPORT LUNS and REQUEST
SENSE commands). The INQUIRY, REPORT LUNS and REQUEST SENSE commands will always be responded with a
GOOD status. Detecting a fault during power on will not terminate execution of the tests nor will it terminate the power on
process.

20.17.2 Self-test via SEND DIAGNOSTIC Command

20.17.2.1 Default Self-test
The default self-test is invoked by the SlfTst bit in the SEND DIAGNOSTIC command. The response is simply a GOOD sta-
tus if the test is successful or a CHECK CONDITION status if the test fails.
The following tests are performed by the default self-test (in the order defined):
1. Spin check is to check if the spindle motor is running at the correct speed.
2. Write, Read and Compare test is a disk read/write test. It writes data to a predefined location in the reserved area and
then reads it back and validates the content. All heads are tested.
3. ECC circuit test is a test for ECC circuit to ensure that errors can be corrected by the circuit.
4. Seek test is a servo test. It validates seeks to 256 random locations out of the full volume.
20.17.2.2 Short and Extended Self-tests
There are two other types of self-tests that may be invoked using the Function Code field in the SEND DIAGNOSTIC com-
mand: a short self-test and an extended self-test. The tests performed in the short and extended self-tests are described later.
The time required by a logical unit to complete its extended self- test is specified in the Extended self-test Completion Time
field in the Control Mode Page. The results of self-test can be retrieved via the LOG SENSE command for Log Page 10.
20.17.2.3 Self-test Modes
There are two modes for short and extended self-tests: a foreground mode and a background mode. These modes are described
in the following clauses.
Foreground mode
When the drive receives a SEND DIAGNOSTIC command specifying a self-test to be performed in the foreground mode, the
drive will return status for that command after the self-test has been completed. While performing a self-test in the foreground
mode, the drive will respond to all commands except INQUIRY, REPORT LUNS, and REQUEST SENSE with a CHECK
CONDITION status, a sense key of NOT READY and an additional sense code of LOGICAL UNIT NOT READY - SELF-
TEST IN PROGRESS.
If the drive is performing a self-test in the foreground mode and a test error occurs, the drive will update the self-test results log
page and report CHECK CONDITION status with a sense key of HARDWARE ERROR and an additional sense code of
LOGICAL UNIT FAILED SELF-TEST. The application client may obtain additional information about the failure by reading
the self-test results log page.
An application client may terminate a self-test that is being performed in the foreground mode using an ABORT TASK,
ABORT TASK SET, or CLEAR TASK SET task management function. If the drive receives an ABORT TASK, ABORT
TASK SET, or CLEAR TASK SET task management function while performing a self-test in the foreground mode, it will
abort the self-test and update the self-test results log page.
Background mode
When the drive receives a SEND DIAGNOSTIC command specifying a self-test to be performed in the background mode, the
drive will return status for that command as soon as the command descriptor block has been validated. After returning status
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