29.6.2.2.2 Data Transmission Mode

In Transmitter mode, the DATAm registers contain the data to be transmitted.

when DATAm is empty, the Transmit Ready bit in the Interrupt Flag Status and Clear register is set (INTFLAG.TXRDYm). Writing to DATAm will clear this bit.

A transmit underrun condition occurs if a new data word needs to be transmitted before it has been written to DATAm. Then, the Transmit Underrun bit in INTFLAG will be set (INTFLAG.TXURm). This interrupt can be cleared by writing a '1' to it. The Transmit Data when Underrun bit in the Serializer n Control register (SERCTRLm.TXSAME) configures whether a zero data word is transmitted in case of underrun (SERCTRLm.TXSAME=0), or the previous data word for the current transmit slot number is transmitted again (SERCTRLm.TXSAME=1).