UMTS/HSPA Module Series
UC20 Hardware Design
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Large
Capacitance
Capacitor
Module
RTC
Core
R
VRTC
Figure 17: RTC Supply from Capacitor
3.10. UART Interface
The module provides two UART interfaces: main UART interface and debug UART interface. The
following shows the different features.
Main UART interface supports 9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600bps
baud rate, the default is 115200bps, while autobauding is not supported. This interface can be used
for data transmission, AT communication or firmware upgrade.
Debug UART interface supports 115200bps. It can be used for GNSS NMEA sentences output.
USB interface supports software debug and firmware upgrade by default.
The module is designed as the DCE (Data Communication Equipment), following the traditional
DCE-DTE (Data Terminal Equipment) connection. The following tables show the pin definition of these
two UART interfaces.
Table 9: Pin Definition of the Main UART Interface
Pin Name
Pin No.
I/O
Description
Comment
RI
62
DO
Ring indicator.
1.8V power domain.
DCD
63
DO
Data carrier detection.
1.8V power domain.
CTS
64
DO
Clear to send.
1.8V power domain.
RTS
65
DI
Request to send.
1.8V power domain.
NOTE
