STMicroelectronics STM32WL5 Series Reference Manual page 1247

RM0453
Bit 18 SBKF: Send break flag
Bit 17 CMF: Character match flag
Bit 16 BUSY: Busy flag
Bits 15:11 Reserved, must be kept at reset value.
Bit 10 CTS: CTS flag
Note: If the hardware flow control feature is not supported, this bit is reserved and kept at
Bit 9 CTSIF: CTS interrupt flag
Note: If the hardware flow control feature is not supported, this bit is reserved and kept at
Bit 8 Reserved, must be kept at reset value.
Bit 7 TXE: Transmit data register empty/TXFIFO not full
Note: This bit is used during single buffer transmission.
Low-power universal asynchronous receiver transmitter (LPUART)
This bit indicates that a send break character was requested. It is set by software, by writing
1 to the SBKRQ bit in the LPUART_CR3 register. It is automatically reset by hardware during
the stop bit of break transmission.
0: Break character transmitted
1: Break character requested by setting SBKRQ bit in LPUART_RQR register
This bit is set by hardware, when a the character defined by ADD[7:0] is received. It is
cleared by software, writing 1 to the CMCF in the LPUART_ICR register.
An interrupt is generated if CMIE = 1in the LPUART_CR1 register.
0: No Character match detected
1: Character Match detected
This bit is set and reset by hardware. It is active when a communication is ongoing on the RX
line (successful start bit detected). It is reset at the end of the reception (successful or not).
0: LPUART is idle (no reception)
1: Reception on going
This bit is set/reset by hardware. It is an inverted copy of the status of the CTS input pin.
0: CTS line set
1: CTS line reset
reset value.
This bit is set by hardware when the CTS input toggles, if the CTSE bit is set. It is cleared by
software, by writing 1 to the CTSCF bit in the LPUART_ICR register.
An interrupt is generated if CTSIE = 1 in the LPUART_CR3 register.
0: No change occurred on the CTS status line
1: A change occurred on the CTS status line
reset value.
TXE is set by hardware when the content of the LPUART_TDR register has been transferred
into the shift register. It is cleared by a write to the LPUART_TDR register.
An interrupt is generated if the TXEIE bit =1 in the LPUART_CR1 register.
0: Data register full
1: Data register not full
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