What Is the SMBus Controller?
The SMBus controller enables simple, two wire communication between the motherboard and key system components. Short for "system management bus," this component allows for an operating system to handle power supply commands, or for the control of system fans. The specifications governing the SMBus controller, which is owned by Intel, allows for flexibility in its use.
How Is the SMBus Used?
Though the usage of the SMBus varies, it mostly relates to power control and monitoring functions. For example, laptops with the Smart Power function use the SMBus controller to allow the operating system to detect the computer's battery levels. The bus, however, was developed to be as open to different uses as possible. For example, some developers have found ways to use the SMBus to more easily load firmware onto a device.
Problems With the SMBus Controller
Typically, the SMBus controller is unnoticeable when installed correctly, as it will simply take on the label of the monitored devices connected to it. If SMBus controllers are not installed properly in an operating system, however, it will appear in the Device Manager. If this is the case, try downloading updated SMBus controller drivers from your motherboard manufacturer.
History of SMBus
The first version of SMBus standards were release in 1995. Developed by Intel, SMBus was based on the I2C standards originally developed by Phillips. The SMBus standards were more robust than the I2C standards. The latest SMBus standard, 2.0, was released in 2000.
References & Resources
- Battery University: The Smart Battery
- RTC Magazine: Simplify Development with Cost-Effective Bootloading Using I2C/SMBus Interfaces
- Dell: An Exclamation Mark Appears on the SM Bus Controller in Device Manager in Microsoft® Windows® XP
- Lenovo: AMD SMBus Device Driver for Windows 8.1
- Intel: SMBus Controller Not Recognized by Windows
- System Management Bus: Specification 2.0
- SMBus Specifications