8042 KEYBOARD CONTROLLER AND REAL TIME CLOCK FUNCTIONAL
DESCRIPTION
The FDC37C93xFR is a Ultra I/O, Real Time
Clock and Universal Keyboard Controller that is
designed for intelligent keyboard management
in desktop computer applications. The Ultra I/O
supports a floppy disk Controller, two 16550-
type serial ports, one ECP/EPP parallel port and
two IDE drive interfaces with support
for four drives.
Controller uses an 8042 microcontroller CPU
core. This section concentrates on the
FDC37C93xFR enhancements to the 8042. For
general information about the 8042, refer to the
"Hardware Description of the 8042" in the 8-Bit
Embedded Controller Handbook.
The Universal Keyboard
P24
P25
P21
P20
KIRQ
MIRQ
GP25
GP20 (WD Timer)
8042A
LS05
P27
P10
KDAT
KCLK
MCLK
MDAT
P26
TST0
P23
TST1
P22
P11
FIGURE 5 - KEYBOARD AND MOUSE CONTROLLER
KIRQ is the Keyboard IRQ
MIRQ is the Mouse IRQ
GP25 - Port 21 is GP25's alternate function output, and can be used to create a GATEA20 signal from
the FDC37C93xFR.
GP20 - This General purpose output can be configured as the 8042 Port 2.0 which is typically used to
create a "keyboard reset" signal. The 8042's P20 can be used to optionally reset the Watch Dog
Timer.
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SMSC [ SMSC CORPORATION ]
