37.3.13.2 10-Bit Host Transmission

When address buffers are enabled (ABD = 0), I2CxADB1 is loaded with the client high address, I2CxADB0 is loaded with the client low address, and I2CxCNT is loaded with a count value. Once software sets the Start (S) bit, the MMA bit is set, and hardware transmits the 10-bit client address. Upon the 8th falling SCL edge of the transmitted address low byte, since TXBE = 1, the MDR and I2CxTXIF bits are set, and hardware stretches the clock while the DMA loads I2CxTXB with data. Once the DMA loads I2CxTXB, the TXBE, MDR and I2CxTXIF bits are cleared by hardware, and the DMA waits for the next occurrence of I2CxTXIF being set.

When address buffers are disabled (ABD = 1), software must load I2CxTXB with the client high address to begin transmission. Once the client high address has been transmitted, I2CxTXIF will be set, triggering the DMA to load I2CxTXB with client low address. Once the DMA loads I2CxTXB with the client low address, the TXBE, MDR and I2CxTXIF bits are cleared by hardware, and the DMA waits for the next occurrence of I2CxTXIF being set.