User's Manual

UMTS/HSDPA Module Series
UC15 Hardware Design
UC15_Hardware_Design Confidential / Released 36 / 78
The logic levels are described in the following table.
Table 11: Logic Levels of Digital I/O
3.9.1. The Connection of UART
The connection between module and host via UART port is very flexible. Three connection ways are
illustrated as below.
UART port connection is shown as below when it is applied in modulation-demodulation.
TXD
RXD
RTS
CTS
DTR
DCD
RI
TXD
RXD
RTS
CTS
DTR
DCD
RING
Module
GND
GND
PC
Figure 14: Connection of Full Functional UART Port
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.
Parameter Min. Max. Unit
V
IL
-0.3 0.91 V
V
IH
1.69 2.9 V
V
OL
0 0.45 V
V
OH
2.15 2.6 V