Super I/O
From Wikipedia, the free encyclopedia
"Super I/O" is the name given to a class of I/O controller integrated circuits that began to be used on personal computer motherboards in the late 1980s. A super I/O chip combines interfaces for a variety of low bandwidth devices. The functions provided usually include:
- a floppy disk controller
- a parallel port (commonly used for printers)
- one or more serial ports
- a mouse interface
- a keyboard interface.
A super I/O chip may also have other interfaces, as for a joystick or infrared port. By combining many functions in a single chip, the number of parts needed on a motherboard is reduced, thus reducing the cost.
The original super I/O chips communicated with the CPU via a connection with an ISA bus. With the evolution away from ISA towards use of the PCI bus, the Super I/O chip was often the biggest remaining reason for continuing inclusion of ISA on the motherboard.
Modern super I/O chips use the Low Pin Count (LPC) bus instead of ISA for communication with the CPU. This normally occurs through an LPC interface on the southbridge chip of the motherboard.
