Real-Time Clock, Cmos Sram, And Battery; I/O Controller - Intel D845GRG Using Manual

The Desktop Boards support Laser Servo (LS-120) diskette technology through the IDE interfaces.
The BIOS supports booting from an LS-120 drive.
✏
NOTE
The BIOS will always recognize an LS-120 drive as an ATAPI floppy drive. To ensure correct
operation, do not configure the drive as a hard disk drive.
1.7.3.2 SCSI Hard Drive Activity LED Connector
The SCSI hard drive activity LED connector is a 1 x 2-pin connector that enables an add-in
SCSI controller to use the same LED as the onboard IDE controller. For proper operation, this
connector should be wired to the LED output of the add-in SCSI controller. The LED indicates
when data is being read from, or written to, both the add-in SCSI controller and the IDE controller.

1.7.4 Real-Time Clock, CMOS SRAM, and Battery

A coin-cell battery (CR2032) powers the real-time clock and CMOS memory. When the computer
is not plugged into a wall socket, the battery has an estimated life of three years. When the
computer is plugged in, the standby current from the power supply extends the life of the battery.
The clock is accurate to ± 13 minutes/year at 25 ºC with 3.3 VSB applied.
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INTEGRATOR'S NOTE
If the battery and AC power fail, custom defaults, if previously saved, will be loaded into CMOS
RAM at power-on.

1.8 I/O Controller

The I/O controller (SMSC LPC47M172 or National Semiconductor PC87372) provides the
following features:
•
One serial port
•
One parallel port with Extended Capabilities Port (ECP) and Enhanced Parallel Port
(EPP) support
•
Serial IRQ interface compatible with serialized IRQ support for PCI systems
•
PS/2-style mouse and keyboard interfaces
•
Interface for one 1.2 MB or 1.44 MB diskette drive
•
Intelligent power management, including a programmable wake-up event interface
•
PCI power management support
•
Two fan tachometer inputs
The BIOS Setup program provides configuration options for the I/O controller.
For information about
SMSC LPC47M172 I/O controller
National Semiconductor PC87372 I/O controller
Product Description
Refer to
http://www.smsc.com
http://www.natsemi.com
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