FIC a440 Service Manual
Software Functional Overview
3-16
FIC A440 Series Service Manual
3.4
3.4
3.4
3.4 Power
Management
Power Management
Power Management
Power Management
This section provides the Power Management software function of the notebook.
3.4.1 General
Requirements
The BIOS meet the following general Power Management requirements:
• Compliant with APM 1.2 Specification
• Full APM Support for Windows 95 Fuel Gauge and Power Management functionality
• Support for Suspend-to-RAM and Suspend-to-Disk mode
• Support for Resume on Modem Ring while in STR Mode. This is controlled by a
CMOS Setup option
• Power Management must be OS independent
• Power Management must support Resume-on-Time
3.4.2 Power Management Mode Definitions
A particular implementation of system power management may use some or all of the
depicted states. A brief description of the state’s characteristics is:
Full-On Mode
The system state where no devices are power managed and the system can respond to
applications with maximum performance.
Doze Mode
The CPU clock is slow down and all other devices are still full on. (Similar to IDLE mode –
Transparent to user)
Stand By (POS) Mode
A suspend state where all motherboard components are still powered-on except for the system
clock generator device. The PCI and CPU buses are driven to the inactive idle state. The
system memory is powered and refreshed by the memory bridge, and the graphics frame
buffer is powered and refreshed by the graphic chip. The system provides a 32KHz clock
(SUSCLK) in this suspend mode to support refresh of these memory subsystems. Only an
enabled “resume event” can bring the system out of the powered-on suspend (POS) state. The
Banister also provides a resume timer that allows the system to resume after a programmed
time has elapsed.
Suspend to RAM (STR) Mode
A suspend state where all motherboard components are powered-off. The CPU and PCI
busses are powered off. All devices connected to the CPU and PCI busses must either be
powered-off or isolate their bus interfaces. The system memory is powered and refreshed by
the memory bridge, and the graphics frame buffer is powered and refreshed by the graphics
chip. The system provides a 32 KHz clock (SUSCLK) in this suspend mode to support refresh
of these memory subsystems. Only an enabled “resume event” can bring the platform out of
the Suspend-to-RAM (STR) state.
Suspend to Disk (STD) Mode:
A suspend state where the context of the entire system is saved to disk, all motherboard
components are powered-off, and all clocks are stopped. Any enabled “resume event”, such as
depicted states. A brief description of the state’s characteristics is:
Full-On Mode
The system state where no devices are power managed and the system can respond to
applications with maximum performance.
Doze Mode
The CPU clock is slow down and all other devices are still full on. (Similar to IDLE mode –
Transparent to user)
Stand By (POS) Mode
A suspend state where all motherboard components are still powered-on except for the system
clock generator device. The PCI and CPU buses are driven to the inactive idle state. The
system memory is powered and refreshed by the memory bridge, and the graphics frame
buffer is powered and refreshed by the graphic chip. The system provides a 32KHz clock
(SUSCLK) in this suspend mode to support refresh of these memory subsystems. Only an
enabled “resume event” can bring the system out of the powered-on suspend (POS) state. The
Banister also provides a resume timer that allows the system to resume after a programmed
time has elapsed.
Suspend to RAM (STR) Mode
A suspend state where all motherboard components are powered-off. The CPU and PCI
busses are powered off. All devices connected to the CPU and PCI busses must either be
powered-off or isolate their bus interfaces. The system memory is powered and refreshed by
the memory bridge, and the graphics frame buffer is powered and refreshed by the graphics
chip. The system provides a 32 KHz clock (SUSCLK) in this suspend mode to support refresh
of these memory subsystems. Only an enabled “resume event” can bring the platform out of
the Suspend-to-RAM (STR) state.
Suspend to Disk (STD) Mode:
A suspend state where the context of the entire system is saved to disk, all motherboard
components are powered-off, and all clocks are stopped. Any enabled “resume event”, such as