Input/Output (I/O) Controller; Real-Time Clock - Intel CA810E Product Manual

Input/Output (I/O) Controller

The SMSC LPC47M102 super I/O controller handles the exchange of information between the
processor and external devices, such as a mouse, keyboard, or printer that are connected to the
computer. The controller features:
•
Low pin count (LPC) interface
•
Two serial ports
•
Infrared port (IrDA
•
One parallel port with Extended Capabilities Port (ECP) and Enhanced Parallel Port (EPP)
support
•
PS/2–style mouse and keyboard interfaces
•
Interface for one 1.2 MB, 1.44 MB, or 2.88 MB diskette drive
•
Intelligent power management, including a programmable wake-up event interface
•
Dual game port interface
•
MPU-401 MIDI support
•
Fan control:
 Two fan speed control outputs
 Two fan tachometer inputs
The BIOS Setup program provides configuration options for the I/O controller.

Real-Time Clock

The desktop board has a time-of-day clock and 100-year calendar that will roll over to 2000 at the
turn of the century. A battery on the desktop board keeps the clock current when the computer is
turned off.
NOTE
The recommended method of accessing the date in systems with Intel desktop boards is indirectly
from the Real-Time Clock (RTC) via the BIOS. The BIOS on Intel desktop boards and baseboards
contains a century checking and maintenance feature that checks the least two significant digits of
the year stored in the RTC during each BIOS request (INT 1Ah) to read the date and, if less than
80 (i.e., 1980 is the first year supported by the PC), updates the century byte to 20. This feature
enables operating systems and applications using the BIOS date/time services to reliably
manipulate the year as a four-digit value.
For more information on proper date access in systems with Intel desktop boards, see the Intel
Web site at:
http://support.intel.com/support/year2000/index.htm
†
1.0 compliant)
Desktop Board Features
15