IT8712 is a Super I/O chip handling serial ports, parallel port, FDC,
keyboard, mouse, thermometers, voltage measurement, etc. It's installed
on GigaByte motherboards (probably others too). This chip is configurable
from BIOS setup, which requires reboot with every change. The following
Linux utility allows to modify all registers at runtime, for example
changing serial port mode from IrDA to standard and vice versa. 

See it8712(8) manpage for details.