The host data register I/O location (DATA)
provides access to the host transmit and receive data
buffers. Reading valid data or writing data to be transmitted can be successfully
done only when SCL is held low by the host
(STATUS.CLKHOLD is set). An exception is reading the last data byte after the stop
condition has been sent.
Accessing DATA.DATA auto-triggers I2C
bus operations. The operation performed depends on the state of CTRLB.ACKACT,
CTRLB.SMEN and the type of access (read/write).
When CTRLC.DATA32B=1, read and write transactions from/to the DATA register are 32
bit in size. Otherwise, reads and writes are 8 bit.