Getac

HDD reports a different power control mechanism
from that of ODD, linking to device driver layer for
status check. BIOS sets ACPI Script Language (ASL )
code to get the device status and take power-
control actions.
Turning off ODD directly will cause system errors. BIOS
must check the status of ODD cyclically and determine
the next step accordingly. The power of ODD will only
be allowed to be turned off if no disk exists and idle
after a setting time.
For those plug-and-play (PnP) devices, that turning off
power when they are not in use is basic approach for
power saving. Getac’s research and development center
has integrated the resources of Hardware, Software,
Driver and Application teams to develop a convenient,
smart utility, G-Manager (Figure 2) to control the power
of PnP devices. Users will be able to define power control
mechanisms of such devices by themselves in order to
optimize the utility to meet their requirements.
G-Manager also provides the default “Ultra Power
Saving” mode that helps turn off all PnP devices to
enable ease in use.
In addition to PnP devices, collaboration among Hardware, Software, Driver and Mechanical engineers at Getac
has developed technologies for fixed devices. As these devices are irremovable and do not offer random control,
software must check the status of such devices by reading the registers in chipset or driver, while the embedded
controller and BIOS are in charge of switching the devices on or off automatically based on device status.
01
Power saving for
static devices
02
Power Saving for
Dynamic Devices
A. Optical Disk Drive (ODD) B. Hard Disk Drive (HDD)
[Figure 2] G-Manager
Similar to Intel’s Auto Connect Battery Saver (ACBS) technology, this is a more efficient power-saving method
developed by Getac to turn off the LAN chip power completely. The circuit is compatible with 10MB, 100MB and
1GB network systems. An embedded controller (EC) will check the LAN cable status by the signal provided from
the LAN signal detection glue logic. The glue logic will generate a logic low level signal periodically while the LAN
cable is connected to a RJ45 connector and linked to the network, and the signal will keep logic high permanently
if no LAN cable is connected. Chipset follows the information from EC to deal with bus isolation and initialization.
Both EC and Chipset must work closely to enable the ACBS function. On the one hand, EC must get the grant signal
from Chipset to make sure the bus is isolated and then turns off the LAN chip power of.
C. LAN
Accuracy power
source design
Intrinsic static idle power consumption is the characteristic of semiconductor devices. No matter the system is in
standby, sleep or power down mode, there will be a fix current to continuously deplete energy. Giving an equation
P = I × V, the P value will vary by V when the I value is fixed. The P value will decrease when V decreases. In most
cases, engineers will increase the voltage from DC/DC output modestly to compensate the propagation loss and
make sure the end point chips receive correct power supply. Getac engineers reduce the power propagation loss
by improving the mother board PCB layout design technique and the stable DC/DC system design. By doing so,
Getac engineers implement an accuracy power supply system that meets the requirement of chips and reduces
unnecessary power depletion.
03
Getac Power Management Technology Technology Brief