The System Management Bus (SMBus) is essentially a derivative of the I2C bus. The standard has been developed by Intel and is now maintained by the SBS Forum.
The main application of the SMBus is to monitor critical parameters on PC motherboards and in embedded systems. There are, for example, many supply voltage monitor, temperature monitor, and fan control ICs with an SMBus interface available.
There are some interesting differences between the I2C bus and the SMBus:
- Packet Error Checking (PEC)
- Timeout for transfers
- Standardized transfer types
- ALERT line
- SUSPEND line
- Power down/up
- maximum bit rate of 100 kbit/s
References
Tools
- Tracii XL 2.0 is an interface and monitor offering support for the SMBus.