Seagate ST91000642NS ユーザーズマニュアル

16

Constellation.2 Serial ATA Product Manual, Rev. B

 

Each power condition has a set of current, saved and default settings. Default settings are not modifiable. 
Default and saved settings persist across power-on resets. The current settings do not persist across power-on 
resets. At the time of manufacture, the default, saved and current settings are in the Power Conditions log 
match.

• Automatic power transitions which are triggered by expiration of individual power condition timers. These 

timer values may be customized and enabled using the Extended Power Conditions (EPC) feature set using 
the standardized Set Features command interface.

• Immediate host commanded power transitions may be initiated using an EPC Set Features "Go to Power 

Condition" subcommand to enter any supported power condition. Legacy power commands Standby Imme-
diate and Idle Immediate also provide a method to directly transition the drive into supported power condi-
tions. 

• Any command which requires the drive to enter the PM0: Active state (media access)

• Power on reset

Check Power Mode Command 

• Reports the current power state of the drive

Identify Device Command

• EPC Feature set supported flag

• EPC Feature enabled flag is set if at least one Idle power condition timer is enabled

Power Condition Log reports the following for each power condition 

• Nominal recovery time from the power condition to active

• If the power condition is Supported, Changeable, and Savable

• Default enabled state, and timer value

• Saved enabled state, and timer value

• Current enabled state, and timer value

S.M.A.R.T. Read Data Reports

• Attribute 192 - Emergency Retract Count

• Attribute 193 - Load/Unload Cycle Count

Idle_a

81

H

Reduced electronics

Idle_b

82

H

Heads unloaded. Disks spinning at full RPM

Idle_c

83

H

Heads unloaded. Disks spinning at reduced RPM

Standby_z

00

H

Heads unloaded. Motor stopped (disks not spinning)