---
name: "superio"
section: "4"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/superio"
---

# superio(4)

Super I/O controller and bus driver

## NAME

**superio** – Super I/O controller and bus driver

## SYNOPSIS

To compile this driver into the kernel, place the following line in your kernel configuration file:

**device superio**

Alternatively, to load the driver as a module at boot time, place the following line in [loader.conf(5)](/loader.conf/5.md):

```
superio_load="YES"
```

## DESCRIPTION

Super I/O is an I/O controller that combines various low-bandwidth devices that can be functionally unrelated otherwise. A typical Super I/O can contain devices such as

- a floppy disk controller

- a parallel port

- a serial port

- a PS/2 mouse and keyboard controller

- a hardware monitoring controller

- a watchdog timer

- a controller for general purpose input-output

The **superio** driver provides support for devices residing in the Super I/O controller that can only be accessed or discovered using the controller's interface. Some of the Super I/O devices have standardized interfaces. Such devices either use well-known legacy resources or they are advertised via ACPI or both. They can be configured either using ISA bus hints or they are auto-configured by [acpi(4)](/acpi/4.md). The **superio** driver is not designed to interact with that kind of devices. They can be handled by their respective drivers without any knowledge of the Super I/O specifics. For instance, [fdc(4)](/fdc/4.md) provides access to the floppy disk controller.

There are other Super I/O devices that do not have any standardized interface. Drivers for those devices can be written using facilities of the **superio** driver.

The driver itself attaches to the ISA bus as all supported controllers are accessed via LPC I/O ports.

The **superio** driver is unusual as it is both a controller driver for a variety of Super I/O controllers and a bus driver for supported devices in those controllers.

## HARDWARE

The **superio** driver supports a multitude of Super I/O controllers produced by Nuvoton, formerly known as Winbond, and ITE, namely:

- Fintek F81803

- Fintek F81865

- Nuvoton NCT5104D/NCT6102D/NCT6106D rev. A and B+

- Nuvoton NCT5585D

- Nuvoton NCT6116D

- Nuvoton NCT6775

- Nuvoton NCT6776

- Nuvoton NCT6779

- Nuvoton NCT6791

- Nuvoton NCT6792

- Nuvoton NCT6793

- Nuvoton NCT6795

- Nuvoton NCT6796D-E

- Winbond 83627HF/F/HG/G/S/THF/EHF/DHG/UHG/DHG-P

- Winbond 83637HF

- Winbond 83667HG/HG-B

- Winbond 83687THF

- Winbond 83697HF/UG

## SEE ALSO

[superio(9)](/superio/9.md)

## HISTORY

The **superio** driver was written by Andriy Gapon ⟨*avg@FreeBSD.org*⟩.