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as not active for a sustained period of time, the device will be brought to some lower power state
as soon as practicable.
With the exception of thermal management, if a device has a demand upon it, full performance
and bandwidth will be given to that device for as long as the user demands it. Power management
should not cause the user to sacrifice performance or functionality in order to get longer battery
life. The longer battery life should be obtained through managing resources not in use.
Pathological cases of measuring CPU speed or trying to periodically check for reaction time of
specific peripherals can detect the presence of power management. However, in general, since
the device I/O is trapped and the device managed in SMI, the power management of devices
should be invisible to the user and the application.
Thermal management is the only overriding concern to the power management architecture. By
definition, thermal management only comes into play when the resources of the computer are
used in such a way as to accumulate heat and operate many devices at maximum bandwidth to
create a thermal problem inside the unit. This thermal problem indicates a danger of damaging
components due to excessively high operating temperatures. Hence, in order to maintain a safe
operating environment, there may be occasions where we have to sacrifice performance in order
to achieve operational safety.
Heuristic power management is designed to operate and adapt to the user while the user is using
it. It is the plug and play equivalent for power management. There are no entries in BIOS Setup
which are required to be set by the user in order to optimize the computers battery life or
operation.
The only BIOS Setup entries are for condition information for suspend/resume
operations. Normal operations and power management are done automatically. (see chapter 3
BIOS Setup for details).
1.5.7.1 PMU Timers
There are several devices related timers available on the V1-LS chip. Each timer may have zero
or more devices assigned to the timer for the purpose of retriggering the timer.
Table 1- 13
PMU Timers List
Item
Video timer
Timer value
System activities
and timer retriggers
Since the power management is implemented by linking with APM
interface closely, the APM function in Win95 or Win3.1 must be
enabled and set to advanced level for optimum power management
and the driver that installed in system must be Acer authorized and
approved.
Heuristic time-out table: 30sec, 1min, 2min, 3min, 4min, 5min, 6min, 7min, 8min,
9min, 10min, 20min, 30min(if AC plugged-in)
System activities
−
The video display (CRT and LCD) is in power saving mode.
Timer retriggers
−
KBC, PS/2 mouse, serial mouse, (if defined in SETUP) will retrigger the timer..
Descriptions
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