Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification
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21.17.1 Reset Sources

There are four sources of resets detected by the target:

21.17.2 Reset Actions

The action taken by the drive following a reset is dependent on the source of the reset.

21.17.2.1 Power-On reset and Self-Initiated reset

These two reset conditions cause the following to be performed in the order shown:
• A power-up sequence
• A startup sequence is necessary to put the drive in a ready state
These reset conditions cause the following actions:
• If the reset occurs during the power-up sequence, the power-up sequence is re-started.
• If the auto-start option is enabled and a start-up sequence has not yet completed, the start-up sequence is restarted.
Note: The power-up sequence is not re-run, since it has already completed.
• If the reset occurs while a physical sector is being written, the WRITE operation is disabled at the end of the current
sector. The media is not corrupted if power is maintained to the end of the current sector.
21.18 Diagnostics
The drive will execute Power on Diagnostics at power on time to assure the correct operation of the drive by validating com-
ponents (ROM, RAM, Sector Buffer, EEPROM, HDC, Spindle Motor, Actuator), checking stored information in the Reserved
Area and EEPROM, and verifying fault detects circuits.
Self-test can be invoked by issuing a SEND DIAGNOSTIC command.

21.18.1 Power on Diagnostics

At power on time the following tests are executed:
1. Validation of ROM and EEPROM
2. RAM test for internal RAM
3. Test and Initialize HDC registers
4. RAM test for Sector Buffer
5. Start Spindle Motor (if Auto spin up enable)
Reset Name Reset Source
Power-On Reset This is the signal generated by the hardware at initial power-on
Self-Initiated reset This is a software-generated reset that occurs when a catastrophic error is detected by
the microcode.
LIP Reset This is a LIP(AL_PS_PD) primitive sequence where the AL_PD matches the AL_PA
of the drive.
Target Reset This is an FCP_CMD IU with the TARGET RESET TMF flag set.
Reset LUN This is a FCP_CMD IU with the RESET LUN TMF flag set.