26.6.3.4 Quick Command
Setting the Quick Command Enable bit in the Control B register (CTRLB.QCEN) enables quick command. When quick command is enabled, the corresponding Interrupt flag (INTFLAG.SB or INTFLAG.MB) is set immediately after the client acknowledges the address. At this point, the software can either issue a Stop command or a repeated start by writing CTRLB.CMD or ADDR.ADDR.