POWER MANAGEMENT OVERVIEW
The Versa 2000 series system uses power management features to prolong system battery
life.
The CPU implements a System Management Interrupt (SMI) function that works
transparently with the operating system and application software. When activated, the
processor mode changes to real mode. Unique “SM-RAM” containing power management
software is mapped at address 30000h-3FFFFh. This activity is inherent to the system and
does not require any adjustment to the operating system or application software.
The power management program is located in ROM at location EA000h-0EFFFh. In on-
board DRAM, the software is physically allocated at 0D0000h-0DFFFFh.
Use Auto Setup to select specific power management options. For information on how to
select these options, see Section 2.
NOTE:
Some power management features are
unavailable when an NEC docking station is
connected.
System Power Management
The system power management consists of the following operation modes. These modes
are:
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Active Mode
In active mode, the system uses maximum power. It operates
with the default clock speed (75 MHz). The system continues to run at this
speeds unless overwritten by the power management features.
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Suspend Mode
When the system is powered on, but not in use it enters into
Automatic Suspend mode after a specified amount of time (default timeout is 10
minutes). This shut-down mechanism conserves system power while allowing the
user to return to complete the work at any time.
Or, the system can be put into Suspend mode using the Suspend/Resume switch.
Slide the switch to activate Suspend mode; slide again to resume active mode.
Suspend mode causes the CPU clock to stop, local devices to shut down, and
register values to be stored in RAM. System RAM is put into a slow refresh state.
Local Power Management
Use Auto Setup to select one of four power management settings for local devices. These
include Longest Battery Life, Personal Setup, Maximum Performance and Off. The power
management levels are also available during AC operation. See Section 2 for specific
procedures on using Auto Setup to select the power management settings.
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