System Management Bus
(SMBus)
Specification
Version 2.0
August 3, 2000

The System Management Bus (SMBus) is a two-wire interface through which various system component
chips can communicate with each other and with the rest of the system. It is based on the principles of
operation of I2C*.
SMBus provides a control bus for system and power management related tasks. A system may use SMBus
to pass messages to and from devices instead of tripping individual control lines. Removing the individual
control lines reduces pin count. Accepting messages ensures future expandability.
With System Management Bus, a device can provide manufacturer information, tell the system what its
model/part number is, save its state for a suspend event, report different types of errors, accept control
parameters, and return its status.