RM0377 Datasheet, PDF (722/862 Pages) STMicroelectronics – This reference manual targets application developers

RM0377
Low-power universal asynchronous receiver transmitter (LPUART)
25.5
LPUART low-power mode
Table 112. Effect of low-power modes on the LPUART
Mode
Description
Sleep
Low-power run
Low-power sleep
Stop
Standby
No effect. USART interrupt causes the device to exit Sleep mode.
No effect.
No effect. USART interrupt causes the device to exit Low-power sleep
mode.
The LPUART is able to wake up the MCU from Stop mode when the
UESM bit is set and the LPUART clock is set to HSI16 or LSE.
The MCU wakeup from Stop mode can be done using either the standard
RXNE or the WUF interrupt.
The LPUART is powered down and must be reinitialized when the device
has exited from Standby mode.
25.6
LPUART interrupts
Table 113. LPUART interrupt requests
Interrupt event
Event flag
Transmit data register empty
CTS interrupt
Transmission Complete
Receive data register not empty (data ready to be read)
Overrun error detected
Idle line detected
Parity error
Noise Flag, Overrun error and Framing Error in multibuffer
communication.
Character match
Wakeup from Stop mode
1. The wUF interrupt is active only in Stop mode.
TXE
CTSIF
TC
RXNE
ORE
IDLE
PE
NF or ORE or FE
CMF
WUF⁽¹⁾
Enable
Control bit
TXEIE
CTSIE
TCIE
RXNEIE
IDLEIE
PEIE
EIE
CMIE
WUFIE
The LPUART interrupt events are connected to the same interrupt vector (see Figure 228).
• During transmission: Transmission Complete, Clear to Send, Transmit data Register
empty or Framing error interrupt.
• During reception: Idle Line detection, Overrun error, Receive data register not empty,
Parity error, Noise Flag, Framing Error, Character match, etc.
These events generate an interrupt if the corresponding Enable Control Bit is set.
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