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/
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Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
Figure 23-8 Reception using DMA
In multi-buffer communication mode, the error flag will be set when there is a frame error, overrun or noise error. An
interrupt will be generated if the error interrupt is enabled (USART_CTRL3.ERRIEN=1).
23.4.8
Hardware flow control
USART supports hardware flow control. The purpose is to coordinate the sending and receiving parties so that the
data will not be lost. The connection method is shown in the following figure.
Figure 23-9 hardware flow control between two USART
RX line
RXDNE flag
Data 0
Data 1
Data N
cleared by DMA
DMA request
DMA TXCF flag
set by hardware
clear by software
DMA reads Data0
from USART_DAT
DMA reads Data1
from USART_DAT
DMA reads DataN
from USART_DAT
set by hardware
DMA transfer
is complete
TX control
RX control
RX control
TX control
DEVICE 1
DEVICE 2
RX
TX
TX
RX
CTS
RTS
RTS
CTS