Athena III User Manual Rev A.03
www.diamondsystems.com
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15
4.2.9
Power Supply
Athena III runs on a fixed input of +5 VDC +/-5%. In addition, a pin is available for users to attach +12VDC;
however this voltage is routed only to the LCD backlight connector and the PC/104 expansion bus connectors. No
on-board circuit connects to +12V. Every circuit connects to +5V or to supplies derived from +5V.
4.2.10
Battery Backup
Athena III includes a backup battery for CMOS RAM and real-time clock backup. The battery is mounted on the
top side of the board. The battery provides a minimum of 3 years backup capability at 25
o
C with the system
powered off.
A connector is provided to disable the on-board battery and enable use of an external battery instead. External
battery voltage requirement is 3.3V +/- 10%.
4.2.11
Watchdog Timer
A programmable watchdog timer (WDT) is included to provide an automatic reset in case of system hang. The
WDT may be retriggered either by a software command or a digital input. The system will reset when the WDT is
enabled and expires.
The WDT circuitry is integrated into the SCH31121 SIO chip.
4.2.12
BIOS
The AMI BIOS includes the following key features:
Boot from LAN (PXE) and USB as well as C: and D:
User selectable Master boot device selection
Free boot sequence configuration
Support for various LCD configurations supported by the video chipset
Console (display and keyboard) redirection to serial port
BIOS recovery through USB attached storage or other means
Configurable default settings in battery-less configurations
Initialize USB keyboard & mouse
Customizable splash screen