Intermec 6100 参照ガイド

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The layer immediately above the APM BIOS includes the operating system

power management driver.  For DOSĆbased systems, the device driver is

NORDOSPM.EXE.  For Windows applications, the device driver is

NORWINPM.DRV, and VPOWERD.386 is included.  The operating system driver

is responsible for the power management strategy.  This includes system power

state and device power state transitions.  The driver is also responsible for the

application interfaces.
The highest layer includes applications that are APMĆaware.  Applications reĆ

ceive power messages only from the APM driver.  Applications can communicate

with either the APM driver or the APM BIOS.
The objective of APM is to control the power usage of the system according to

system activity.  As system activity decreases, APM reduces the power consumpĆ

tion of system resources until the system is brought into a suspend state.
There are two methods of powerĆlevel control:

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The APM BIOS manages CPU/core logic, display, and backlight power in

the background, based on device activity.

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An APM driver (NORDOSPM.EXE or NORWINPM.DRV and

VPOWERD.386) participates in managing power levels via function calls to

the APM software interface.

The APM driver has three default system power states:

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Ready ( full on )

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Idle

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APM suspend.

The primary difference between states is the latency needed for the system to

reach full operation.  Power consumption and performance are greatest in the

Ready state and decrease with each succeeding state.

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System Ready is the default mode when the system is not engaged in power

management.

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System Idle is the first level of power management.  The CPU is halted and

the system clock speed is reduced.  Transitions from Idle to Ready are

instantaneous.

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System Suspend is the second level of power management.  The CPU clock

is stopped and devices are placed into the power state defined by the apĆ

plication for System Suspend.  The device power state for suspend can be

any power state defined for that device.  The exact definition of a device

power state during suspend is performed by using the Set Power State, Get

Power State, and Enable/Disable Device Power Management functions.

Transitions from suspend to ready generally take 100 milliseconds.

System power states are managed through the use of activity monitors, activity

timers, and function calls from APM device drivers or APMĆaware applications.
Activity monitors are hardwareĆspecific devices that watch for I/O to predefined

I/O devices and I/O addresses.  The PEN*KEY 6100 system has activity moniĆ

tors for the following I/O devices.  Whenever one of these devices is accessed, a

bit in the activity monitor for the device becomes set.