20.5.7.3 Host Mode Transmission with DMA

Once the host has addressed the client, ND/A (I2CxCON2[18]) has to be set to the indicated data transmission and then load the first data to the transmit buffer. The Transmit Buffer Status bit TBF (I2CxSTAT1[0]) is cleared when the I2CxTRN does not contain any transmit data. At this point, the transmit interrupt (I2CxTXIF) can trigger DMA to load another byte into the buffer. The host hardware sets the TBF bit, and the DMA continues to write the next data until the packet size (PSZ) becomes 0.