Input/Output (I/O) Controller; Real-Time Clock - Intel cc820 Product Manual

Input/Output (I/O) Controller

The SMSC LPC47M102 ultra 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 the following:
•
Two serial ports
•
One parallel port with Extended Capabilities Port (ECP) and Enhanced Parallel Port (EPP)
support
•
Mouse and keyboard controller
•
Diskette drive controller supporting two drives on one cable
•
MIDI/Game port
•
Fan control

Real-Time Clock

The desktop board has a time-of-day clock and 100-year calendar that will rollover 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 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 about the year 2000 capability of systems with Intel desktop boards, see the
Intel World Wide Web site:
http://support.intel.com/support/year2000/index.htm
Desktop Board Features
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