SMBus

The System Management Bus (abbreviated to SMBus or SMB) is a simple two-wire bus， derived from I?C and used for communication with low-bandwidth devices on a motherboard， especially power related chips such as a laptop's rechargeable battery subsystem (see Smart Battery Data)。 Other devices might include temperature， fan or voltage sensors， lid switches and clock chips。 PCI add-in cards may connect to an SMBus segment。 A device can provide manufacturer information， indicate its model/part number， save its state for a suspend event， report different types of error， accept control parameters and return status。