1.11 Advanced Power Management (APM)

Emergency Unload other than Unload is performed when the power is shut down while the heads are still loaded on the disk.

The product supports the Emergency Unload a minimum of 20,000 times. When the power is shut down, the controlled Unload cannot be executed. Therefore, the number of Emergency other than Unload is specified.

1.10.1 Recommended power-off sequence

We recommend cutting the power supply of the HDD for this device after the Head Unload operation completes. The recommended power supply cutting sequence for this device is as follows:

1)Disk Flush

Flush Cache command execution.

2)Head Unload

Standby Immediate command execution.

3)Wait Status

Checking whether bit 7 of the status register was set to '0'. (wait to complete STANDBY IMMEDIATE command)

4)HDD power supply cutting

1.11Advanced Power Management (APM)

The disk drive automatically shifts to the power saving mode according to the setting of the APM mode under the idle condition.

The APM mode can be chosen with a Sector Count register of the SET

FEATURES (EF) command.

The disk drive complies with the three kinds of APM modes that a command from the host is required.

FR = 05h : Enable APM

SC = C0h - FEh : Mode-0 Active Idle Low Power Idle

SC = 80h - BFh : Mode-1 Active Idle Low Power Idle (Default)

SC = 01h - 7Fh : Mode-2 Active Idle Low Power Idle Standby

FR = 85h : Disable APM (Set Mode-0)

Active Idle:

The head is in a position of extreme inner in disk

 

medium. (VCM Lock)

C141-E224

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Fujitsu MHV2120BH, MHV2100BH, MHV2080BH, MHV2040BH, MHV2060BH Advanced Power Management APM, Recommended power-off sequence