CARD-PCI/GX Hardware Manual
Rev.A
EPSON
47
5. Power management
5. Power management
5. Power management
5. Power management
This chapter describes SCE8720C’s power-saving functions and power-related matters.
The power-saving function is precisely specified in the BIOS setup menu. SCE8720C’s
power-saving function not only minimizes the system power consumption, but also
minimizes the CPU heat-up to control and protect the temperature.
5.1 Power ON/OFF
The system can select whether or not to control the power supply by software or external
control signals PM0# and PM1#.
When controlling by software or PM0# and PM1# signals, power can be turned ON by
signal from LAN, RING signal or PWSW# signal, and be turned OFF from the software.
For each reference circuit, refer to Appendix A.
5.2 Standby mode
In case of no input from Windows’ keyboard or mouse for a certain period of time, or
PWSW# signal (pulse) input within 4 seconds, the system gets into the standby mode. In
standby mode, the display is turned OFF and the peripheral devices also get into the
power-saving mode. (motors of HDD and FDD are turned OFF.) To return to the
standard operation mode from the standby mode, the power switch input within 4
seconds or keyboard/mouse input is effective. However, whether or not the operation
mode is resumed is determined by the BIOS settings.
5.3 Power supply
V
CC3V
(3.3V)
Supplied to the IO power supply of the CPU chip (Geode GX-LV), companion chip
(Geode CS5530) and S-DRAM.
V
CCCORE
(5V)
Power supply for the DC-DC converter, which generates the CPU’s core power supply.
Input the same power supply as V
CC5V
. Power consumption is highest of all.
V
CC5V
(5V)
Mainly supplied to the Super IO (PC97317).
V
CCSTB
Supplied to the circuit which controls ON/OFF of the power supply. In SCE8720C,
it is supplied to the power supply control circuit of the Super I/O (PC97317). When
ATX power supply is used, it is always supplied from the power supply unit when
the AC cord is connected.
When V
CCSTB
-equivalent power cannot be obtained due to the power supply unit not
capable of ON/OFF control of the power supply, connect V
CC5V
instead.