---
name: "piixpm"
section: "4"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/piixpm"
---

# piixpm(4)

Intel PIIX SMBus controller

## NAME

**piixpm** – Intel PIIX SMBus controller

## SYNOPSIS

**piixpm\* at pci?** **iic\* at piixpm?**

## DESCRIPTION

The **piixpm** driver provides support for the Intel PIIX and compatible Power Management controller. Only the SMBus host interface is supported and can be used with the [iic(4)](/iic/4.md) framework.

Supported chipsets:

- AMD Hudson-2, FCH (KERNCZ)

- ATI SB200, SB300, SB400, SB600, SB700, SB800

- Intel 82371AB (PIIX4), 82440MX

- ServerWorks OSB4, CSB5, CSB6, HT-1000, HT-1100

- SMSC Victory66

## SEE ALSO

[iic(4)](/iic/4.md), [intro(4)](/intro/4.md), [pci(4)](/pci/4.md)

## HISTORY

The **piixpm** driver first appeared in OpenBSD 3.7 to provide support for the power management (ACPI) timer. In OpenBSD 3.9, power management support was dropped in favor of [acpitimer(4)](/acpitimer/4.md) and SMBus functionality was added.

## AUTHORS

The current **piixpm** driver was written by Alexander Yurchenko ⟨*grange@openbsd.org*⟩.

## BUGS

The driver doesn't support I2C commands with a data buffer size of more than 2 bytes.