Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
455
/
631
Functional block diagram
Figure 22-1 USART block diagram
Function description
As shown in the Figure 22-1, the bidirectional communication of any USART needs to use the RX and TX pins of
the external connection. Among them, TX is the output pin for serial data transmission. When the transmitter is active
and not sending data, the TX pin is pulled high. When the transmitter is inactive, the TX pin reverts to the I/O port
configuration. RX is an input pin for serial data reception, data is recovered by oversampling technique.
The data packets of serial communication are transmitted from the sending device to the RX interface of the receiving
TX control
RX control
Interrupt
CTRL register
Buadrate
generate
Wake up
Transmit Shift
Register
Receive Shift
Register
Transmit Data
Register(TDR)
Receive
Data(RDR)
CPU/DMA
IrDA
SIR
ENDEC
BLOCK
Hardware
flow
controller
USART
address
Tx clock
Rx clock
STS
register
BRCF
register
GTP
register
CK
nCTS
nRTS
SW_RX
RX
TX
PCLK