Device Overview

Emergency Unload other than Normal 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 Normal Unload cannot be executed. Therefore, the number of Emergency other than Normal Unload is specified.

Remark:

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

The disk drive shifts to the three kinds of APM modes automatically under the Idle condition.

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

FEATURES(EF) command.

In APM Mode-1, which is the APM default mode, the operation status shifts till it finally reaches "Low Power Idle."

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)

 

1-12

C141-E203-01EN

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Fujitsu MHT2040BH, MHT2060BH, MHT2080BH manual Advanced Power Management