Real-Time Clock, Cmos Sram, And Battery; I/O Controller - Intel D865PERLX Specification

Intel Desktop Board D865PERC/D865PESO Technical Product Specification
1.8.3.2 Serial ATA Interfaces
The ICH5's Serial ATA controller offers two independent Serial ATA ports with a theoretical
maximum transfer rate of 150 MB/s per port. One device can be installed on each port for a
maximum of two Serial ATA devices. A point-to-point interface is used for host to device
connections, unlike Parallel ATA IDE which supports a master/slave configuration and two
devices per channel.
For compatibility, the underlying Serial ATA functionality is transparent to the operating system.
The Serial ATA controller can operate in both legacy and native modes. In legacy mode, standard
IDE I/O and IRQ resources are assigned (IRQ 14 and 15). In Native mode, standard PCI resource
steering is used. Native mode is the preferred mode for configurations using the Windows XP and
Windows 2000 operating systems.
✏
NOTE
Many Serial ATA drives use new low-voltage power connectors and require adaptors or power
supplies equipped with low-voltage power connectors.
For more information, see:
1.8.3.3 SCSI Hard Drive Activity LED Connector (Optional)
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, either the add-in hard drive controller or the
onboard IDE controller (Parallel ATA or Serial ATA).
For information about
The location of the SCSI hard drive activity LED connector on the D865PESO board
The location of the SCSI hard drive activity LED connector on the D865PERC board
The signal names of the SCSI hard drive activity LED connector

1.8.4 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.

1.9 I/O Controller

The I/O controller provides the following features:
32
http://www.serialata.org/
Refer to
Figure 21, page 65
Figure 22, page 66
Table 29, page 66