27.5.3 Master Control A

Writing this bit to '1' enables interrupt on the Master Read Interrupt Flag (RIF) in the Master Status register (TWIn.MSTATUS). A TWI Master read interrupt would be generated only if this bit, the RIF, and the Global Interrupt Flag (I) in CPU.SREG are all '1'.

Writing this bit to '1' enables interrupt on the Master Write Interrupt Flag (WIF) in the Master Status register (TWIn.MSTATUS). A TWI Master write interrupt will be generated only if this bit, the WIF, and the Global Interrupt Flag (I) in CPU.SREG are all '1'.

Writing this bit to '1' enables Quick Command. When Quick Command is enabled, the corresponding interrupt flag is set immediately after the slave acknowledges the address. At this point, the software can either issue a Stop command or a repeated Start by writing either the Command bits (CMD) in the Master Control B register (TWIn.MCTRLB) or the Master Address register (TWIn.MADDR).

Setting the inactive bus timeout (TIMEOUT) bits to a non-zero value will enable the inactive bus time-out supervisor. If the bus is inactive for longer than the TIMEOUT setting, the bus state logic will enter the Idle state.

Writing this bit to '1' enables the Master Smart mode. When Smart mode is enabled, the acknowledge action is sent immediately after reading the Master Data (TWIn.MDATA) register.

Writing this bit to '1' enables the TWI as master.