
Low-power universal asynchronous receiver transmitter (LPUART)
RM0453
1252/1454
RM0453 Rev 2
Bit 6
TC
: Transmission complete
This bit is set by hardware if the transmission of a frame containing data is complete and if
TXE is set. An interrupt is generated if TCIE = 1 in the LPUART_CR1 register. It is cleared
by software, writing 1 to the TCCF in the LPUART_ICR register or by a write to the
LPUART_TDR register.
An interrupt is generated if TCIE = 1 in the LPUART_CR1 register.
0: Transmission is not complete
1: Transmission is complete
Note: If TE bit is reset and no transmission is on going, the TC bit is immediately set.
Bit 5
RXNE
: Read data register not empty
RXNE bit is set by hardware when the content of the LPUART_RDR shift register has been
transferred to the LPUART_RDR register. It is cleared by reading from the LPUART_RDR
register. The RXNE flag can also be cleared by writing 1 to the RXFRQ in the
LPUART_RQR register.
An interrupt is generated if RXNEIE = 1 in the LPUART_CR1 register.
0: Data is not received
1: Received data is ready to be read.
Bit 4
IDLE
: Idle line detected
This bit is set by hardware when an Idle Line is detected. An interrupt is generated if
IDLEIE = 1 in the LPUART_CR1 register. It is cleared by software, writing 1 to the IDLECF
in the LPUART_ICR register.
0: No Idle line is detected
1: Idle line is detected
Note: The IDLE bit is not set again until the RXNE bit has been set (i.e. a new idle line
occurs).
If Mute mode is enabled (MME
=
1), IDLE is set if the LPUART is not mute (RWU
=
0),
whatever the Mute mode selected by the WAKE bit. If RWU
=
1, IDLE is not set.
Bit 3
ORE
: Overrun error
This bit is set by hardware when the data currently being received in the shift register is
ready to be transferred into the LPUART_RDR register while RXNE = 1. It is cleared by a
software, writing 1 to the ORECF, in the LPUART_ICR register.
An interrupt is generated if RXNEIE = 1 or EIE = 1 in the LPUART_CR1 register.
0: No overrun error
1: Overrun error is detected
Note: When this bit is set, the LPUART_RDR register content is not lost but the shift register
is overwritten. An interrupt is generated if the ORE flag is set during multi buffer
communication if the EIE bit is set.
This bit is permanently forced to 0 (no overrun detection) when the bit OVRDIS is set in
the LPUART_CR3 register.