M12 Hardware Design
M12_Hardware_Design_V3.3
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DBG_TXD: Send data to the COM port of computer
DBG_RXD: Receive data from the COM port of computer
The UART3 Port:
TXD3: Send data to the RXD of DTE
RXD3: Receive data from the TXD of DTE
The logic levels are described in the following table.
Table 8: Logic levels of the serial interface
Table 9: Pin definition of the serial interfaces
Interface
Name
Pin
Function
Debug Port
DBG_RXD
9
Receive data of the debug port
DBG_TXD
10
Transmit data of the debug port
UART Port
RI
55
Ring indicator
RTS
58
Request to send
CTS
57
Clear to send
RXD
61
Receive data of the serial port
TXD
60
Transmit data of the serial port
DTR
59
Data terminal ready
DCD
56
Data carrier detection
UART3 Port
TXD3
62
Transmit data of UART3
RXD3
63
Receive data of UART3
3.8.1. UART Port
3.8.1.1. The features of UART Port
Seven lines on UART interface:
Contain data lines TXD and RXD, hardware flow control lines RTS and CTS, other control
lines DTR, DCD and RI.
Parameter
Min
Max
Unit
V
IL
0
0.25×VDD_EXT
V
V
IH
0.75×VDD_EXT
V0.3
V
V
OL
0
0.15×VDD_EXT
V
V
OH
0.85×VDD_EXT
VDD_EXT
V
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