27.3.5 Sleep Mode Operation
The bus state logic and the address recognition hardware continue to operate in all sleep modes. If a client device is in a sleep mode and a Start condition followed by the address of the client is detected, clock stretching is active during the wake-up period until the main clock is available. The host will stop operation in all sleep modes. When the Dual mode is active, the device will wake up only when the Start condition is sent on the client bus.