Real-Time Clock, Cmos Sram, And Battery; Intel ® 82802Ab Firmware Hub (Fwh) - Intel D845PEBT2 Specification

Intel Desktop Board D845PEBT2 Technical Product Specification
✏
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.
For information about
The location of the IDE connectors
The signal names of the IDE connectors
IDE RAID support
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 allows an add-in
hard drive 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 hard drive controller. The LED
indicates when data is being read from, or written to, both the add-in hard drive controller and the
IDE controller.
For information about
The location of the SCSI hard drive activity LED connector
The signal names of the SCSI hard drive activity LED connector

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.
✏
NOTE
If the battery and AC power fail, custom defaults, if previously saved, will be loaded into CMOS
RAM at power-on.
®
1.7.5 Intel 82802AB Firmware Hub (FWH)
The 4 Mbit FWH provides the following:
•
System BIOS program
•
Logic that enables protection for storing and updating of platform information
26
Refer to
Figure 14, page 61
Table 41, page 66
Section 1.8, page 27
Refer to
Figure 14, page 61
Table 42, page 66