Real-Time Clock, Cmos Sram, And Battery - Intel SE7221BA1 Technical Manual

Intel® Entry Server Board SE7221BA1-E TPS
3.3.2.2 Serial ATA Interfaces
The ICH6-R's Serial ATA controller offers four 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 four 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 Conventional bus resource steering is used. Native mode is the preferred mode for
configurations using the Windows* XP and Windows* 2000 operating systems.
3.3.2.3 Serial ATA RAID
The ICH6-R supports RAID (Redundant Array of Independent Drives) level 0 and Raid level 1
on the Serial ATA ports as follows:
•
RAID 0 supports data striping. Two physical drives, of identical size, can be teamed
together to create one logical drive. As data is written or retrieved from the logical
drive, both drives operate in parallel, thus increasing the throughput.
•
RAID 1 supports data mirroring. Two physical drives, of identical size, maintain
duplicate sets of all data on separate disk drives. Level 1 provides the highest data
reliability because two complete copies of all information are maintained.
•
RAID 10 combines both striping and mirroring to provide a high data transfer rates and
data redundancy. Four physical drives, of identical size are required for the RAID
group.
3.3.2.4 RAID Boot Configuration Overview
A RAID array can be created by using the existing Serial ATA ports, correctly configuring the
BIOS, and installing drivers. The following steps are required to successfully establish a RAID
configuration.
1. Enable RAID Support in BIOS.
2. Create a RAID array.
3. Load the RAID driver while installing the Operating System.
4. Format the RAID array.
3.3.2.5 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).
3.3.3

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.
Revision 1.5
Functional Architecture
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