STMicroelectronics STM32WL5 Series - FIFO Disabled); Figure 331. Wake-Up Event Verified (Wake-Up Event = Address Match, FIFO Disabled); Figure 332. Wake-Up Event Not Verified

Universal synchronous/asynchronous receiver transmitter (USART/UART) RM0453
1162/1450 RM0453 Rev 5
Figure 331 shows the USART behavior when the wake-up event is verified.
Figure 331. Wake-up event verified (wake-up event = address match, FIFO disabled)
Figure 332 shows the USART behavior when the wake-up event is not verified.
Figure 332. Wake-up event not verified (wake-up event = address match,
FIFO disabled)
Note: The figures above are valid when address match or any received frame is used as wake-up
event. If the wake-up event is the start bit detection, the USART sends the wake-up event to
the MCU at the end of the start bit.
MSv40856V2
usart_ker_ck
RX line
Idle
Start bit
Rx data 1 Rx data 2
Start bit
Stop bit
Stop bit
OFF
ON
Low-power mode
Startup time
Run mode
Address match event WUF =’1'
USART sends a wakeup event to the MCU
Data reception goes on
MSv40857V2
usart_ker_ck
RX line
Idle
Start bit
Rx data 1
Stop bit
OFF
ON
Low-power mode
Address does not match
Idle
OFF
Startup time