UMTS/HSPA Module Series
UG95 Hardware Design
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3.10. UART Interface
The module provides 7 lines UART interface.
UART interface supports 300, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800
and 921600bps baud rate, and the default is auto-baud rate 4800~115200. This interface can be used for
data transmission, AT communication or firmware upgrade.
The module is designed as the DCE (Data Communication Equipment), following the traditional
DCE-DTE (Data Terminal Equipment) connection. The following table shows the pin definition of UART
interface.
Table 10: Pin Definition of the Main UART Interface
Pin Name
Pin No. I/O
Description
Comment
DTR
30
DI
Data terminal ready
1.8V power domain
RXD
34
DI
Receive data
1.8V power domain
TXD
35
DO
Transmit data
1.8V power domain
CTS
36
DO
Clear to send
1.8V power domain
RTS
37
DI
Request to send
1.8V power domain
DCD
38
DO
Data carrier detection
1.8V power domain
RI
39
DO
Ring indicator
1.8V power domain
The logic levels are described in the following table.
Table 11: Logic Levels of Digital I/O
Parameter
Min.
Max.
Unit
V
IL
-0.3
0.35
V
V
IH
1.3
1.85
V
V
OL
0
0.25
V
V
OH
1.55
1.8
V
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