If you want to look at a hardware implementation then you may consider the Cygnal 8051 derivatives. Some of the Cygnal parts implement the SMBus which is compliant with the System Management Bus Specification, version 1.1 and compatible with the I2C serial bus. Reads and writes to the interface by the processor are byte oriented with the SMBus interface autonomously controlling the serial transfer of the data. It also supports a method of extending the clock-low duration to accommodate devices with different speed capa
bilities on the SMBus. The SMBus may operate as master and/or slave and may function on bus with multiple masters. SMBus provides
control of SDA (serial data), SCL (serial clock) generation and synchronization, arbitration logic, and START/STOP
control and generation.

Michael Karas