UMTS/HSDPA Module
UC15 Hardware Design
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Table 10: Pin Definition of the Main UART Interface
Pin Name Pin No.
I/O
Description
Comment
RI
55
DO
Ring indicator.
2.6V power domain.
DCD
56
DO
Data carrier detection. 2.6V
power
domain.
CTS
57
DO
Clear to send.
2.6V power domain.
RTS
58
DI
Request to send.
2.6V power domain.
DTR
59
DI
Data terminal ready.
2.6V power domain.
TXD
60
DO
Transmit data.
2.6V power domain.
RXD
61
DI
Receive data.
2.6V 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*
VDD_EXT
V
V
IH
0.65* VDD_EXT
V0.3
V
V
OL
0 0.45
V
V
OH
VDD_EXT -0.45
VDD_EXT
V
UART interface supports 300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 230400,
460800bps baud rate, the default is 115200bps, while autobauding is not supported. This interface can be
used for data transmission,
AT communication and firmware upgrade.
3.9.1. The connection of UART
The connection between module and host via UART port is very flexible. Three connection styles are
illustrated as below.
UART Port connection is shown as below when it is applied in modulation-demodulation.
