Editing System Management Bus (section)

====Timing====
*SMBus defines a clock low time-out, TIMEOUT of 35&nbsp;ms. I²C does not specify any timeout limit.
*SMBus specifies T<sub>LOW:SEXT</sub> as the cumulative clock low extend time for a slave device. I²C does not have a similar specification.
*SMBus specifies T<sub>LOW:MEXT</sub> as the cumulative clock low extend time for a master device. Again I²C does not have a similar specification.
*SMBus defines both rise and fall time of bus signals. I²C does not.
*The SMBus time-out specifications do not preclude I²C devices co-operating reliably on the SMBus. It is the responsibility of the designer to ensure that I²C devices are not going to violate these bus timing parameters.