User`s guide

Power Saving Modes Chapter Five - Power Management
79
If the system enters Suspend mode from the above options, it enters the best
power-saving Suspend mode that is supported by the system. When the system
suspends, the following events take place:
•
The video screen is turned off
•
CPU, DMA clocks, and the math co-processor, are powered down
•
All controllable peripheral devices are turned off
C
AUTION
:
If the system is left in DRAM Suspend mode long enough to consume all
battery power, then the Suspend indicator goes out and all unsaved data in
the computer’s memory are lost. The system cannot resume until the
battery is recharged or the TREK 2 is connected to AC power.
The amount of time that the system remains suspended depends on the amount
of battery power remaining. Due to this limitation, you should always save your
data before the system suspends.
Pressing the power button for one second causes the system to resume operation
after entering Suspend. Resuming returns the system’s operation to the point in
your application where the suspend was initiated. This does not mean, however,
that all devices are powered up. When the system resumes, the following events
occur:
•
DRAM refresh memory returns the system to the application that was
running before the Suspend operation
•
The video is turned on.
•
The COM ports are enabled.
•
Then, each device is powered on when it is requested for use by the
system.
The following table summarizes the TREK 2’s power-saving features:
Power Mode Entering Mode Reactivating
System Idle Transits automatically Press any key, Access
HDD
System Standby Transits automatically after
specified time out
Press any key
TABLE 8. Power Management Summary