Memory Map and Registers

Address Offset	Register name	Width (in bits)	Access	Reset value	Section/page
0000_0000h	Status register (UART_SR)	32	R	0000_0000h	UART_SR
0000_0004h	Control register (UART_CR)	32	R/W	0000_0000h	UART_CR
0000_0008h	Receive Data register (UART_RXDR)	32	R	0000_0000h	UART_RXDR
0000_000Ch	Transmit Data register (UART_TXDR)	32	W	0000_0000h	UART_TXDR

Status register (UART_SR)

Position	Field	Description
31-5	Reserved	This field is reserved. This read-only field is reserved and always has the value 0.
4	PE	Parity Error This bit is cleared after reading it. 0   No parity error 1   Parity error detected
3	FE	Framing Error This bit is cleared after reading it. 0   No framing error 1   Framing error detected
2	RXOE	Receive Overrun Error This bit is cleared after reading it. 0   No received overrun error 1   A packet was received but RXNE is asserted
1	TXE	Transmit register Empty 0   The transmit register is full (being sent) 1   The transmit register is empty
0	RXNE	Receive register Not Empty 0   The receive register is empty (no data) 1   The receive register is not empty empty

Control register (UART_CR)

UART_CR contains the control for selecting the UART baudrate, parity, size and stop bits.

Position	Field	Description
31-16	ACC_INCR	Accumulator increment/Baudrate selector The specified accumulator increment determines the baud rate with the formula ACC_INCR = round(baudrate * 2^15 / freq).
15-4	reserved	This field is reserved. This read-only field is reserved and always has the value 0.
3	DS	Data Size selector 0   7-bit data 1   8-bit data
2	S	Stop bit selector 0   1 stop bit 1   2 stop bits
1-0	P	Parity bit selector 00   No parity checks 01   Odd parity 10   Even parity 11   reserved

Receive Data register (UART_RXDR)

Position	Field	Description
31-8	reserved	This field is reserved. This read-only field is reserved and always has the value 0.
7-0	RXD	Receive Data The received data is written to this field. The field is cleared by hardware after being read.

Transmit Data register (UART_TXDR)

Position	Field	Description
31-8	reserved	This field is reserved.
7-0	TXD	Transmit Data Data written to this field is sent through the serial link. The TXE field of the UART_SR shall be sample before writing again to this field to prevent data loss.