27.3.3.4 Dual Mode

The TWI supports Dual mode operation where the host and the client will operate simultaneously and independently. In this case, the Control A (TWIn.CTRLA) register will configure the TWI host, and the Dual Mode Control (TWIn.DUALCTRL) register will configure the TWI client. See the 27.3.2.1 Initialization section for more details about the host configuration.

If used, the following bits must be configured before enabling the TWI Dual mode:
  • The SDA Hold Time (SDAHOLD) bit field in the DUALCTRL register
  • The FM Plus Enable (FMPEN) bit from the DUALCTRL register
The Dual mode can be enabled by writing a ‘1’ to the Dual Control Enable (ENABLE) bit in the DUALCTRL register.