RM0440 Rev 4 1651/2126
RM0440 Universal synchronous/asynchronous receiver transmitter (USART/UART)
1733
Bit 9 PS: Parity selection
This bit selects the odd or even parity when the parity generation/detection is enabled (PCE
bit set). It is set and cleared by software. The parity is selected after the current byte.
0: Even parity
1: Odd parity
This bitfield can only be written when the USART is disabled (UE=0).
Bit 8 PEIE: PE interrupt enable
This bit is set and cleared by software.
0: Interrupt inhibited
1: USART interrupt generated whenever PE=1 in the USART_ISR register
Bit 7 TXEIE: Transmit data register empty
This bit is set and cleared by software.
0: Interrupt inhibited
1: USART interrupt generated whenever TXE =1 in the USART_ISR register
Bit 6 TCIE: Transmission complete interrupt enable
This bit is set and cleared by software.
0: Interrupt inhibited
1: USART interrupt generated whenever TC=1 in the USART_ISR register
Bit 5 RXNEIE: Receive data register not empty
This bit is set and cleared by software.
0: Interrupt inhibited
1: USART interrupt generated whenever ORE=1 or RXNE=1 in the USART_ISR register
Bit 4 IDLEIE: IDLE interrupt enable
This bit is set and cleared by software.
0: Interrupt inhibited
1: USART interrupt generated whenever IDLE=1 in the USART_ISR register
Bit 3 TE: Transmitter enable
This bit enables the transmitter. It is set and cleared by software.
0: Transmitter is disabled
1: Transmitter is enabled
Note: During transmission, a low pulse on the TE bit (‘0’ followed by ‘1’) sends a preamble
(idle line) after the current word, except in Smartcard mode. In order to generate an idle
character, the TE must not be immediately written to ‘1’. To ensure the required duration,
the software can poll the TEACK bit in the USART_ISR register.
In Smartcard mode, when TE is set, there is a 1 bit-time delay before the transmission
starts.