24.5.4 Transmit Data Register High Byte

The USARTn.TXDATAH register holds the ninth data bit in the character to be transmitted when operating with serial frames with nine data bits. When used, this bit must be written before writing to the USARTn.TXDATAL register except if the CHSIZE bits in the USARTn.CTRLC register are is set to 9BIT low byte first, where the USARTn.TXDATAL register should be written first.

This bit is unused in Master SPI mode of operation.

Name: TXDATAH
Offset: 0x03
Reset: 0x00
Property: -

Bit 76543210 
        DATA[8] 
Access R/W 
Reset 0 

Bit 0 – DATA[8] Transmit Data Register

This bit is used when CHSIZE=9BIT in the USARTn.CTRLC register.