Real-Time Clock, Cmos Sram, And Battery; Sst 49Lf004A 4 Mbit Firmware Hub (Fwh) - Intel D810E2CA3 Specification

The D810E2CA3 board supports Laser Servo (LS-120) diskette technology through its IDE
interfaces. An LS-120 drive can be configured as a boot device by setting the BIOS Setup
program's Boot menu to one of the following:
ARMD-FDD (ATAPI removable media device – floppy disk drive)
ARMD-HDD (ATAPI removable media device – hard disk drive)
For information about
The location of the IDE connectors
The signal names of the IDE connectors
BIOS Setup program's Boot menu

1.6.3 Real-Time Clock, CMOS SRAM, and Battery

The real-time clock is compatible with DS1287 and MC146818 components. The clock provides a
time-of-day clock and a multicentury calendar with alarm features and century rollover. The
real-time clock supports 256 bytes of battery-backed CMOS SRAM in two banks that are reserved
for BIOS use.
The time, date, and CMOS values can be specified in the Setup program. The CMOS values can
be returned to their defaults by using the Setup program.
NOTE
If the battery and AC power fail, custom defaults, if previously saved, will be loaded into CMOS
SRAM at power on.
A coin-cell battery 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 3.3 V standby current extends the life of the battery. The clock is accurate to
13 minutes/year at 25 ºC with 3.3 V applied.
For information about
The location of the battery
Proper date access in systems with Intel desktop boards

1.6.4 SST 49LF004A 4 Mbit Firmware Hub (FWH)

The FWH provides the following:
System BIOS
System security and manageability logic that enables protection for storing and updating of
platform information
Desktop Board Description
Refer to
Figure 10, page 58
Table 39, page 62
Table 72, page 101
Refer to
Figure 1, page 14
Section 1.2, page 16
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