Nations Technologies Inc.
Tel
:
+86-755-86309900
:
info@nationstech.com
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
504
/
631
Figure 23-9 CTS flow control
Low power wake up
LPUART can work in STOP2 mode, if the LPUART_CTRL.WUSTP is set, it can wake up the system on EXTI line
23 when a specific waking up event occurs.
The LPUART waking up event can be handled in the following ways (through the LPUART_CTRL.WUSEL[1:0]) :
A waking up event is generated when a start bit is detected
A waking up event is generated when the receive buffer non-empty flag is set
A waking up event is generated when data is received and the first byte matches LPUART_WUDAT[7:0]
A waking up event is generated when data is received and four bytes match LPUART_WUDAT[31:0]
When waking up event occurs, the LPUART_STS.WUF bit will be set.
Interrupt request
Table 23-3 LPUART interrupt requests
Interrupt
Interrupt event
Event flag
Enable bit
LPUART global interrupt
Parity check error
PEF
PEIE
TX complete
TXC
TXCIE
Receive buffer overrun
FIFO_OV
FIFO_OVIE
Receive buffer full
FIFO_FU
FIFO_FUIE
Receive buffer half full
FIFO_HF
FIFO_HFIE
Receive buffer not empty
FIFO_NE
FIFO_NEIE
Wake up in STOP2 mode
WUF
WUFIE
CTSF = 1
CTSF = 1
CTS line
Data register
Data 2
empty
Data 3
Data 2
Data 3
Data 1
empty
Start
Bit
Stop
Bit
Stop
Bit
Start
Bit
Idle
CTS = 1,
Transmit delay
TX line
Writing Data 3 in
Data register
CTS = 0,
Transmit Data 3