Power Management Features; Power Mode; Power Management Commands; Standby Timer - Hitachi HTS542525K9SA00 Specifications

10.5 Power management features

The power management feature set permits a host to modify the behavior in a manner which reduces the power
required to operate. The power management feature set provides a set of commands and a timer that enables a device
to implement low power consumption modes.
HDS72160x0PLATy0 implements the following set of functions:
• A Standby timer
• Idle command
• Idle Immediate command
• Sleep command
• Standby command
• Standby Immediate command

10.5.1 Power mode

Sleep Mode The lowest power consumption when the device is powered on occurs in Sleep Mode. When
in Sleep Mode, the device requires a reset to be activated.
Standby The device interface is capable of accepting commands, but since the media may not be
Mode immediately accessible, there is a delay while waiting for the spindle to reach operating
speed.
Idle Mode In Idle Mode the device is capable of responding immediately to media access requests.
Active Mode The device is executing a command or accessing the disk media with the read look-ahead
function or the write cache function.

10.5.2 Power management commands

Check Power Allows a host to determine if a device is currently in, going to, or leaving standby mode.
Mode
Idle, Idle Move a device to idle mode immediately from the active or standby modes. The idle command
Immediate also sets the standby timer count and starts the standby timer.
Sleep Moves a device to sleep mode. The device's interface becomes inactive at the completion of the
sleep command. A reset is required to move a device out of sleep mode. When a device exits
sleep mode it will enter standby mode.
Standby, Move a device to standby mode immediately from the active or idle modes. The standby
Standby command also sets the standby timer count.
Immediate

10.5.3 Standby timer

The standby timer provides a method for the device to automatically enter standby mode from either active or idle
mode following a host programmed period of inactivity. If the device is in the active or idle mode, the device waits
for the specified time period and, if no command is received, the device automatically enters the standby mode.
If the value of the SECTOR COUNT register on Idle command or Standby command is set to 00h, the standby timer
is disabled.
Deskstar 7K160 Hard Disk Drive Specification
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