20.8.2 Sleep Mode in Host Mode

If Sleep occurs in the middle of a host transmission and the state machine is partially into a transmission as the clocks stop, the behavior of the module will be undefined. Similarly, if Sleep occurs in the middle of a host reception, the module behavior will also be undefined. The transmitter and receiver will stop at Sleep when in Host mode. Register contents are not affected by going into Sleep mode or coming out of Sleep mode; there is no automatic way to prevent Sleep entry if a transmission or reception is pending. The user software must synchronize the Sleep entry with I²C operation to avoid undefined module behavior.