Intel D845GEBV2 BLKD845GERG2-10PK User Manual

Product codes
BLKD845GERG2-10PK
Page of 128
Product Description 
 35 
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 SMSC LPC47M172 I/O controller 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 1.44 MB or 2.88 MB diskette drive 
•  Intelligent power management, including a programmable wake-up event interface 
•  PCI power management support 
The BIOS Setup program provides configuration options for the I/O controller. 
 
For information about  
Refer to 
SMSC LPC47M172 I/O controller 
 
1.9.1 Serial 
Port 
The boards have one serial port connector located on the back panel.  The serial port supports data 
transfers at speeds up to 115.2 kbits/sec with BIOS support. 
 
For information about  
Refer to 
The location of the serial port A connector 
Figure 12, page 60 
 
1.9.2 Parallel 
Port 
The 25-pin D-Sub parallel port connector is located on the back panel.  Use the BIOS Setup 
program to set the parallel port mode.   
 
For information about  
Refer to 
The location of the parallel port connector 
Figure 12, page 60 
Setting the parallel port’s mode 
Table 58, page 101