ST STM32L4 5 Series Reference Manual page 1401

RM0351
Bit 16 RXINV: RX pin active level inversion
This bit is set and cleared by software.
0: RX pin signal works using the standard logic levels (V
1: RX pin signal values are inverted. ((V
This allows the use of an external inverter on the RX line.
This bit field can only be written when the LPUART is disabled (UE=0).
Bit 15 SWAP: Swap TX/RX pins
This bit is set and cleared by software.
0: TX/RX pins are used as defined in standard pinout
1: The TX and RX pins functions are swapped. This allows to work in the case of a cross-wired
connection to another UART.
This bit field can only be written when the LPUART is disabled (UE=0).
Bit 14 Reserved, must be kept at reset value
Bits 13:12 STOP[1:0]: STOP bits
These bits are used for programming the stop bits.
00: 1 stop bit
01: Reserved.
10: 2 stop bits
11: Reserved
This bit field can only be written when the LPUART is disabled (UE=0).
Bits 11:5 Reserved, must be kept at reset value
Bit 4 ADDM7:7-bit Address Detection/4-bit Address Detection
This bit is for selection between 4-bit address detection or 7-bit address detection.
0: 4-bit address detection
1: 7-bit address detection (in 8-bit data mode)
This bit can only be written when the LPUART is disabled (UE=0)
Note: In 7-bit and 9-bit data modes, the address detection is done on 6-bit and 8-bit address
(ADD[5:0] and ADD[7:0]) respectively.
Bits 3:0 Reserved, must be kept at reset value.
Low-power universal asynchronous receiver transmitter (LPUART)
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