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Interpret
as DR
Description
Data
For words to be transmitted:
if the FIFOs are enabled (LCRH.FEN = 1), data written to this location is pushed onto the transmit FIFO
if the FIFOs are not enabled (LCRH.FEN = 0), data is stored in the transmitter holding register (the bottom word of the transmit FIFO).
The write operation initiates transmission from the UART. The data is prefixed with a start bit, appended with the appropriate parity bit (if parity is enabled), and a stop bit.
The resultant word is then transmitted.
For received words:
if the FIFOs are enabled (LCRH.FEN = 1), the data byte and the 4-bit status (break, frame, parity, and overrun) is pushed onto the 12-bit wide receive FIFO
if the FIFOs are not enabled (LCRH.FEN = 0), the data byte and status are stored in the receiving holding register (the bottom word of the receive FIFO).
The received data byte is read by performing reads from this register along with the corresponding status information. The status information can also be read by a read of the RSR register.