Super I/O
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"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, originally as add in cards, later embedded on the motherboards. 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 keyboard and mouse 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.
Fintek, ITE, SMSC, UMC and Winbond make super I/O controllers.
National Semiconductor used to make super I/O controllers but sold their PC Super I/O business to Winbond Electronics Corporation in 2005.
[edit] External links
- List of super I/O chips
- Superiotool allows you to detect which Super I/O you have on your mainboard, and it can provide detailed information about the register contents of the Super I/O. (Linux)
