29.3.5 Sleep Mode Operation

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