Advanced Power Management - Hitachi DK23CA-10 - 10 GB Hard Drive Specifications

(3) Standby Timer
Standby timer is provided for automatic power saving control. The device automatically moves to the
Standby mode if the host does not issue a command within the timer period. The Standby timer is
disabled at power-on. The Standby timer value is changeable using Idle and Standby commands.
The timer can be set up to 30 minutes.

6.3.2.6.2 Advanced Power Management

The host can select the power saving control pattern by Advanced Power management (APM). The device
performs an intelligent power saving control based on the selected pattern by host.
Using Set Feature command and Sector Count register can set the APM operation mode. The Sector count
value is related to the performance level and the power consumption level. If the Sector Counter value
is set to 01h, the power consumption is getting better, but the performance is getting worse. If the large
Sector Count is set to FEh, the performance is getting better sacrificing the power consumption. The device
has five levels of APM operation mode(APM mode 0,1,2,3 and 4) depending on the Sector Counter values
from 01h to FEh.
(1) Command Set
Using the following command, the APM control can be set the mode and reset the mode.
- Set Feature command, Enable Advanced Power Management sub-command.
(Command Code = EFh, Features = 05h)
Set Feature command, Disable Advanced Power Management sub-command.
-
(Command Code = EFh, Features = 85h)
The Enable Advanced Power Management sub-command enables the APM operation set by the Sector
Count register. The Disable Advanced Power Management sub-command disables the APM operation.
If the APM operation is disabled, the device performs APM mode 0.
The APM mode can be confirmed by Identify Device command as follows:
Identify Device Information Word 83 Bit 3: This bit is always set to "1" and indicates the APM
-
operation is supported.
- Identify Device Information Word 86 Bit 3: IF this bit is set to "1", it indicates the APM operation is
enabled.
Identify Device Information Word 91: This word reports an operation mode set by Set Feature
-
command and Enable Advanced Power Management sub-command.
K6602637
Rev.3
02.27.01
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